Screw thread - Knowledge

1758: 616: 1725: 958: 1745: 741: 1944:, ANSI Y14.6 defines standards for indicating threaded parts. Parts are indicated by their nominal diameter (the nominal major diameter of the screw threads), pitch (number of threads per inch), and the class of fit for the thread. For example, “.750-10 UNC-2A” is male (A) with a nominal major diameter of 0.750 inches, 10 threads per inch, and a class-2 fit; “.500-20 UNF-1B” would be female (B) with a 0.500-inch nominal major diameter, 20 threads per inch, and a class-1 fit. An arrow points from this designation to the surface in question. 1920:) was created. With continental Europe and much of the rest of the world turning to SI and ISO metric screw thread, the UK gradually leaned in the same direction. The ISO metric screw thread is now the standard that has been adopted worldwide and is slowly displacing all former standards, including UTS. In the U.S., where UTS is still prevalent, over 40% of products contain at least some ISO metric screw threads. The UK has completely abandoned its commitment to UTS in favour of ISO metric threads, and Canada is in between. 906: 446: 1893:). Therefore, in theory, one might expect that by the start of World War II, the problem of screw thread interchangeability would have already been completely solved. Unfortunately, this proved to be false. Intranational interchangeability was widespread, but international interchangeability was less so. Problems with lack of interchangeability among American, Canadian, and British parts during World War II led to an effort to unify the inch-based standards among these closely allied nations, and the 1331: 833: 825: 248: 1901:, with the hope that they would be adopted universally. (The original UTS standard may be found in ASA (now ANSI) publication, Vol. 1, 1949.) UTS consists of Unified Coarse (UNC), Unified Fine (UNF), Unified Extra Fine (UNEF) and Unified Special (UNS). The standard was widely taken up in the UK, although a small number of companies continued to use the UK's own British standards for Whitworth (BSW), British Standard Fine (BSF) and British Association (BA) microscrews. 256: 31: 1127:, would have a pitch diameter 0.0005 × 3 = 0.0015 inch larger than base pitch diameter and would thus result in cutting an internal thread with a looser fit than say an H2 tap. Metric uses D or DU limits which is the same system as imperial, but uses D or DU designators for over and undersized respectively, and goes by units of 0.013 mm (0.51 mils). Generally taps come in the range of H1 to H5 and rarely L1. 949:

which is less than caliper measurement of the male major diameter (outside diameter, OD). For example, tables of caliper measurements show 0.69 female ID and 0.75 male OD for the standards of "3/4 SAE J512" threads and "3/4-14 UNF JIS SAE-J514 ISO 8434-2". Note the female threads are identified by the corresponding male major diameter (3/4 inch), not by the actual measurement of the female threads.

972:) of a particular thread, internal or external, is the diameter of a cylindrical surface, axially concentric to the thread, which intersects the thread flanks at equidistant points. When viewed in a cross-sectional plane containing the axis of the thread, the distance between these points being exactly one half the pitch distance. Equivalently, a line running parallel to the axis and a distance 1809:, proposing a new standard to replace the US' poorly standardized screw thread practice. Sellers simplified the Whitworth design by adopting a thread profile of 60° and a flattened tip (in contrast to Whitworth's 55° angle and rounded tip). The 60° angle was already in common use in America, but Sellers's system promised to make it and all other details of threadform consistent. 1859:, which defined the new international metric thread standards as having the same profile as the Sellers thread, but with metric sizes. Efforts were made in the early 20th century to convince the governments of the U.S., UK, and Canada to adopt these international thread standards and the metric system in general, but they were defeated with arguments that the 38:. The operator rotates the small vertical bevel gear in the center. Through mechanical advantage this causes the horizontal bevel gears (at far left and far right, with threaded center holes) to rotate. Their rotation raises or lowers the two long vertical threaded shafts - as they are not free to rotate. 1812:

The Sellers thread, easier to produce, became an important standard in the U.S. during the late 1860s and early 1870s, when it was chosen as a standard for work done under U.S. government contracts, and it was also adopted as a standard by highly influential railroad industry corporations such as the

1066:

A general-purpose micrometer (flat anvil and spindle) is used over a set of three wires that rest on the thread flanks, and a known constant is subtracted from the reading. (The wires are truly gauge pins, being ground to precise size, although "wires" is their common name.) This method is called the

1047:

of fit for ranges of thread sizes. At one extreme, no allowance is provided by a class, but the maximum PD of the external thread is specified to be the same as the minimum PD of the internal thread, within specified tolerances, ensuring that the two can be assembled, with some looseness of fit still

89:

is sufficient to prevent linear motion being converted to rotary, that is so the screw does not slip even when linear force is applied, as long as no external rotational force is present. This characteristic is essential to the vast majority of its uses. The tightening of a fastener's screw thread is

724:

Coarse threads are those with larger pitch (fewer threads per axial distance), and fine threads are those with smaller pitch (more threads per axial distance). Coarse threads have a larger threadform relative to screw diameter, where fine threads have a smaller threadform relative to screw diameter.

1982:

Another common inspection point is the straightness of a bolt or screw. This topic comes up often when there are assembly issues with predrilled holes as the first troubleshooting point is to determine if the fastener or the hole is at fault. ASME B18.2.9 "Straightness Gage and Gaging for Bolts and

948:

In order to fit a male thread into the corresponding female thread, the female major and minor diameters must be slightly larger than the male major and minor diameters. However this excess does not usually appear in tables of sizes. Calipers measure the female minor diameter (inside diameter, ID),

884:

The major diameter of threads is the larger of two extreme diameters delimiting the height of the thread profile, as a cross-sectional view is taken in a plane containing the axis of the threads. For a screw, this is its outside diameter (OD). The major diameter of a nut cannot be directly measured

1717: 888:

The major diameter of external threads is normally smaller than the major diameter of the internal threads, if the threads are designed to fit together. But this requirement alone does not guarantee that a bolt and a nut of the same pitch would fit together: the same requirement must separately be

815:

Coarse threads are more resistant to stripping and cross threading because they have greater flank engagement. Coarse threads install much faster as they require fewer turns per unit length. Finer threads are stronger as they have a larger stress area for the same diameter thread. Fine threads are

1873:

During the late 19th and early 20th centuries, engineers found that ensuring the reliable interchangeability of screw threads was a multi-faceted and challenging task that was not as simple as just standardizing the major diameter and pitch for a certain thread. It was during this era that more

1027:

Provided that there are moderate non-negative clearances between the root and crest of the opposing threads, and everything else is ideal, if the pitch diameters of a screw and nut are exactly matched, there should be no play at all between the two as assembled, even in the presence of positive

940:

As shown in the figure at right, threads of equal pitch and angle that have matching minor diameters, with differing major and pitch diameters, may appear to fit snugly, but only do so radially; threads that have only major diameters matching (not shown) could also be visualized as not allowing

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of 1916. Standards seen here overlap with those found elsewhere marked as ASME and SAE standards and with the later Unified Thread Standard (UTS) of 1949 and afterward. One can see the theme of how later standards reflect a degree of continuation from earlier standards, sometimes with hints of

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of screw threads has evolved since the early nineteenth century to facilitate compatibility between different manufacturers and users. The standardization process is still ongoing; in particular there are still (otherwise identical) competing metric and inch-sized thread standards widely used.

668:

threadforms, their lead and pitch are the same. Single-start means that there is only one "ridge" wrapped around the cylinder of the screw's body. Each time that the screw's body rotates one turn (360°), it has advanced axially by the width of one ridge. "Double-start" means that there are two

1931:

Even today, over a half century since the UTS superseded the USS and SAE series, companies still sell hardware with designations such as "USS" and "SAE" to convey that it is of inch sizes as opposed to metric. Most of this hardware is in fact made to the UTS, but the labeling and cataloging

932:

The minor diameter is the lower extreme diameter of the thread. Major diameter minus minor diameter, divided by two, equals the height of the thread. The minor diameter of a nut is its inside diameter. The minor diameter of a bolt can be measured with go/no-go gauges or, directly, with an

601: 1013:, together, would fully describe the thread form. Knowledge of PD determines the position of the sharp-V thread form, the sides of which coincide with the straight sides of the thread flanks: e.g., the crest of the external thread would truncate these sides a radial displacement 1983:

Screws" was developed to address this issue. Per the scope of the standard, it describes the gage and procedure for checking bolt and screw straightness at maximum material condition (MMC) and provides default limits when not stated in the applicable product standard.

811:

imply higher quality. The terms when used in reference to screw thread pitch have nothing to do with the tolerances used (degree of precision) or the amount of craftsmanship, quality, or cost. They simply refer to the size of the threads relative to the screw diameter.

983:

form of the thread, having flanks coincident with the flanks of the thread under test, at exactly 50% of its height. We have assumed that the flanks have the proper shape, angle, and pitch for the specified thread standard. It is generally unrelated to the major

1388:(ISO) in 1947. Although metric threads were mostly unified in 1898 by the International Congress for the standardization of screw threads, separate metric thread standards were used in France, Germany, and Japan, and the Swiss had a set of threads for watches. 485:

sometimes refer to all design aspects taken together (cross-sectional shape, pitch, and diameters), but commonly refer to the standardized geometry used by the screw. Major categories of threads include machine threads, material threads, and power threads.

1285:

series. The seal provided by a threaded pipe joint is created when a tapered externally threaded end is tightened into an end with internal threads. For most pipe joints, a good seal requires the application of a separate sealant into the joint, such as

669:"ridges" wrapped around the cylinder of the screw's body. Each time that the screw's body rotates one turn (360°), it has advanced axially by the width of two ridges. Another way to express this is that lead and pitch are parametrically related, and the 676:

Whereas metric threads are usually defined by their pitch, that is, how much distance per thread, inch-based standards usually use the reverse logic, that is, how many threads occur per a given distance. Thus, inch-based threads are defined in terms of

876:), thread sizes are there to ensure that threads do not strip at the tensile strength limits for the parent material. The minimum limits for internal, and maximum limits for external, threads are there to ensure that the threads fit together. 1854:

thread standards were evolving, which usually employed 60° profiles. Some of these evolved into national or quasi-national standards. They were mostly unified in 1898 by the International Congress for the standardization of screw threads at

394:

In artillery projectiles, anything that screws into the projectile must be given consideration as to what will happen when the projectile is fired, e.g., anything that screws into the base from the bottom of the projectile must be left hand

1781:

made interchangeable V-thread machine screws a practical commodity. During the next 40 years, standardization continued to occur on the intra- and inter-company levels. No doubt many mechanics of the era participated in this zeitgeist;

1250:. In the case of female threads, tap drill charts typically specify sizes that will produce an approximate 75% thread. A 60% thread may be appropriate in cases where high tensile loading will not be expected. In both cases, the 1206:

of the pitch from the dimension over the tips of the "fundamental" (sharp cornered) triangles. The resulting flats on the crests of the male thread are theoretically one eighth of the pitch wide (expressed with the notation

1415:, which has slightly different specifications, and has been technically obsolete since 1949. The old national standard is compatible with the newer unified standard, but is long out of date. This unified standard includes: 800:-20 belongs to the UNF series (Unified National Fine). Similarly, M10 (10 mm nominal outer diameter) as per ISO 261 has a coarse thread version at 1.5 mm pitch and a fine thread version at 1.25 mm pitch. 528:. Truncation occurs (and is codified in standards) for practical reasons—the thread-cutting or thread-forming tool cannot practically have a perfectly sharp point, and truncation is desirable anyway, because otherwise: 681:(TPI). Pitch and TPI describe the same underlying physical property—merely in different terms. When the inch is used as the unit of measurement for pitch, TPI is the reciprocal of pitch and vice versa. For example, a 1178:

A perfectly sharp 60° V-thread will have a depth of thread ("height" from root to crest) equal to 0.866 of the pitch. This fact is intrinsic to the geometry of an equilateral triangle — a direct result of the basic

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long-ago intracompany origins. For example, compare the 6–32, 8–32, 10–24, and 10–32 options in this table with the UTS versions of those sizes, which are not identical but are so close that interchange would work.

1123:. For imperial, H or L limits are used which designate how many units of 0.0005 inch over or undersized the pitch diameter is from its basic value, respectively. Thus a tap designated with an H limit of 3, denoted 1667:

Fahrradgewinde (Fg) (English: bicycle thread) is a German bicycle thread standard (per DIN 79012 and DIN 13.1), which encompasses a lot of CEI and BSC threads as used on cycles and mopeds everywhere (

1159:

To achieve a predictably successful mating of male and female threads and assured interchangeability between males and between females, standards for form, size, and finish must exist and be followed.

1960:

There are many ways to generate a screw thread, including the traditional subtractive types (for example, various kinds of cutting ; molding; casting ; forming and rolling; grinding; and occasionally

1396:

In particular applications and certain regions, threads other than the ISO metric screw threads remain commonly used, sometimes because of special application requirements, but mostly for reasons of

1254:

is not affected. The balancing of truncation versus thread strength is similar to many engineering decisions involving the strength, weight and cost of material, as well as the cost to machine it.

294:

By common convention, right-handedness is the default handedness for screw threads. Therefore, most threaded parts and fasteners have right-handed threads. Left-handed thread applications include:

380:

In a situation where neither threaded pipe end can be rotated to tighten or loosen the joint (e.g. in traditional heating pipes running through several rooms in a building). In such a case, the

1310:

understood the screw principle, and left drawings showing how threads could be cut by machine. In the 1500s, screws appeared in German watches, and were used to fasten suits of armor. In 1569,

1928:; U.S. auto parts factories long ago developed the ability to conform to the ISO standards, and today very few parts for new cars retain inch-based sizes, regardless of being made in the U.S. 1035:, or minimum difference, between the PDs of the internal and external threads has to generally be provided for, to eliminate the possibility of deviations from the ideal thread form causing 1031:

However, this ideal condition would in practice only be approximated and would generally require wrench-assisted assembly, possibly causing the galling of the threads. For this reason, some

542:

The roots and crests of mating male and female threads need clearance to ensure that the sloped sides of the V meet properly despite error in pitch diameter and dirt and nick-induced burrs.

1183:. It is independent of measurement units (inch vs mm). However, UTS and ISO threads are not sharp threads. The major and minor diameters delimit truncations on either side of the sharp V. 673:

that relates them, the number of starts, very often has a value of 1, in which case their relationship becomes equality. In general, lead is equal to pitch times the number of starts.

267:. Most threads are oriented so that the threaded item, when seen from a point of view on the axis through the center of the helix, moves away from the viewer when it is turned in a 1246:

in the case of female threads, or by slightly reducing the diameter of the threaded area of workpiece in the case of male threads, the latter effectively reducing the thread's

1235:

value. For example, a 75% thread sacrifices only a small amount of strength in exchange for a significant reduction in the force required to cut the thread. The result is that

1318:, but the method did not gain traction and screws continued to be made largely by hand for another 150 years. In the 1800s, screw manufacturing began in England during the 1649:

Aerospace inch threads (UNJ) – ISO 3161, controlled root radius on male threads for greater fatigue strength with larger minor diameter on female threads to clear radius.

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to varying degrees (that is, the tip of the triangle is cut short). A V-thread in which there is no truncation (or a minuscule amount considered negligible) is called a

1355:

Additional product standards identify preferred thread sizes for screws and nuts, as well as corresponding bolt head and nut sizes, to facilitate compatibility between

1797:. During the 1840s through 1860s, this standard was often used in the United States as well, in addition to myriad intra- and inter-company standards. In April 1864, 579:, but any angle can be used. The cross section to measure this angle lies on a plane which includes the axis of the cylinder or cone on which the thread is produced. 449:

Different (and incompatible) threads including (from left) M12 left hand, standard M12, M12x1.5 (fine), M12x1.25 (fine), 1/2" UNF, 1/2" UNC, 1/2" BSW, and 1/2" BSF

1705: 1352:

Standard threads are commonly identified by short letter codes (M, UNC, etc.) which also form the prefix of the standardized designations of individual threads.

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root-crest clearances. This is the case when the flanks of the threads come into intimate contact with one another, before the roots and crests do, if at all.

816:

less likely to vibrate loose as they have a smaller helix angle and allow finer adjustment. Finer threads develop greater preload with less tightening torque.

1885:

in pursuit of reliable interchangeability. Classes of fit were standardized, and new ways of generating and inspecting screw threads were developed (such as

221:. Generally speaking, the threads on an external surface are considered male, while the ones on an internal surface are considered female. For example, a 2272: 1870:

created an "SAE series" of screw thread sizes reflecting parentage from earlier USS and American Society of Mechanical Engineers (ASME) standards.

1130:

The pitch diameter of a thread is measured where the radial cross section of a single thread equals half the pitch, for example: 16 pitch thread =

1793:

created a design that, through its adoption by many British railway companies, became a standard for the United Kingdom and British Empire called

860:: Industry standards specify minimum (min.) and maximum (max.) limits for each of these, for all recognized thread sizes. The minimum limits for 1385: 1175:

that can be expressed as a fraction of the pitch value. The UTS and ISO standards codify the amount of truncation, including tolerance ranges.

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may even provide for negative allowances, where the PD of the screw is greater than the PD of the nut by at least the amount of the allowance.

1664:(Pg) (German) is an old German 80° thread (DIN 40430) that remained in use until 2000 in some electrical installation accessories in Germany. 1748:

A table of standard sizes for machine screws as provided by the American Screw Company of Providence, Rhode Island, USA, and published in a

2395:"ASME 125th Anniversary: Special 2005 Designation of Landmarks: Profound Influences in Our Lives: The United States Standard Screw Threads" 995:) diameters, especially if the crest and root truncations of the sharp-V form at these diameters are unknown. Everything else being ideal, 165:

Both moving objects linearly and simultaneously measuring the movement, combining the two aforementioned functions, as in a leadscrew of a

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was adopted by the Screw Thread Standardization Committees of Canada, the United Kingdom, and the United States on November 18, 1949, in

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Where the rotation of a shaft would cause a conventional right-handed nut to loosen rather than to tighten due to applied torque or to

85:, which is the linear distance the screw travels in one revolution. In most applications, the lead of a screw thread is chosen so that 1171:

Screw threads are almost never made perfectly sharp (no truncation at the crest or root), but instead are truncated, yielding a final

1067:

3-wire method. Sometimes grease is used to hold the wires in place, helping the user to juggle the part, mic, and wires into position.

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Quentin R. Skrabec, Jr. (2005). "The Metallurgic Age: The Victorian Flowering of Invention and Industrial Science". p. 169. McFarland

2178: 1408: 1322:. In these times, there was no such thing as standardization. The bolts made by one manufacturer would not fit the nuts of another. 1224:), although the actual geometry definition has more variables than that. A full (100%) UTS or ISO thread has a height of around 0.65 1063:, called a thread mic or pitch mic, which has a V-anvil and a conical spindle tip, contacts the thread flanks for a direct reading. 365:

In gas welding the flammable gas supply uses left-handed threads, while the oxygen supply if there is one has a conventional thread

2509:

Oberg, Erik; Jones, Franklin D.; Horton, Holbrook L.; Ryffel, Henry H. (1996), Green, Robert E.; McCauley, Christopher J. (eds.),

1825:(USS thread). Over the next 30 years the standard was further defined and extended and evolved into a set of standards including 2126: 2394: 1757: 2589: 2573: 2524: 2480: 1687: 91: 588: 2659: 1099:. Classes include 1, 2, 3 (loose to tight); A (external) and B (internal); and various systems such as H and D limits. 200: 50:

structure used to convert between rotational and linear movement or force. A screw thread is a ridge wrapped around a

2608: 2499: 2211: 1836: 1821:. Other firms adopted it, and it soon became a national standard for the U.S., later becoming generally known as the 1733: 1493: 897:

of the nut threads, one must also ensure that the clearances are not so excessive as to cause the fasteners to fail.

225:

has male threads, while its matching hole (whether in nut or substrate) has female threads. This property is called

2101: 1839:

were also developed and refined for small instrumentation and electrical equipment. These were based on the metric

1728:

A good summary of screw thread standards in current use in 1914 was given in Colvin FH, Stanley FA (eds) (1914):

1977: 2235: 1850:

During this era, in continental Europe, the British and American threadforms were well known, but also various

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used in some plumbing installations for the delivery of fluids under pressure have a threaded section that is

1196: in) threads is the theoretical major diameter of the male thread, which is truncated (diametrically) by 1909: 1822: 1513: 945:, due to the unused spaces between the threads, must be minimized so as not to overly weaken the fasteners. 657:

is the distance along the screw's axis that is covered by one complete rotation of the screw thread (360°).

1482: 1467: 1378: 1282: 17: 1262:

Tapered threads are used on fasteners and pipe. A common example of a fastener with a tapered thread is a

1924:

of industries produces market pressure in favor of phasing out minority standards. A good example is the

1548: 1239:

wear is reduced, the likelihood of breakage is lessened and higher cutting speeds can often be employed.

1147:

in the pitch actual pitch diameter of the thread is measured at the radial cross section measures 0.03125

2546: 1306:, who briefly wrote on spirals as well as designed several simple devices applying the screw principle. 2259: 1874:

complicated analyses made clear the importance of variables such as pitch diameter and surface finish.

1794: 1461: 1953: 1556: 1519: 1231:

Threads can be (and often are) truncated a bit more, yielding thread depths of 60% to 75% of the 0.65

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made for the minor and pitch diameters of the threads. Besides providing for a clearance between the

615: 336: 539:

upon cutting, and will be too susceptible to additional future burring resulting from dents (nicks);

184: 158:

Measuring by correlating linear motion to rotary motion (and simultaneously amplifying it), as in a

2230:. Giesecke, Frederick E. (Frederick Ernest), 1869-1953. (4th ed.). New York: Macmillan. 1987. 1886: 1814: 1343: 2080: 1693: 2511: 2445: 2427: 2013: 1894: 1677: 1404: 1374: 1368: 1180: 914: 777: 346:

The hand-tightened nut holding the fan blade to the motor spindle in many designs of oscillating

299: 2382: 961:

Variants of snug fit. Only threads with matched PDs are truly snug, axially as well as radially.

1998: 1965: 1863:

of the necessary retooling would drive some firms from profit to loss and hamper the economy.

1474: 1397: 1084: 271:

direction, and moves towards the viewer when it is turned counterclockwise. This is known as a

67: 1724: 1407:(UTS), is the dominant thread standard used in the United States and Canada. It is defined in 712:. Another wave analogy is that pitch and TPI are inverses of each other in a similar way that 653:

are closely related concepts. They can be confused because they are the same for most screws.

405:

to cause the cross slide to move away from the operator when the leadscrew is turned clockwise

2345: 2028: 2003: 1818: 1744: 1319: 1274: 1096: 957: 436:) have a left-hand thread to deter theft, because they cannot be used in other light fixtures 2053: 1773:

The first historically important intra-company standardization of screw threads began with

1555:, is a special 0.8-inch diameter × 36 thread-per-inch (TPI) Whitworth thread form used for 1432: 1278: 885:(as it is obstructed by the threads themselves) but it may be tested with go/no-go gauges. 740: 506: 422: 280: 78: 1736:

standards are discussed. The SAE series was not mentioned—at the time this edition of the

90:

comparable to driving a wedge into a gap until it sticks fast through friction and slight

8: 2307: 1941: 1925: 1778: 1613:

suspension bolts (in some countries only; some have gone entirely metric, others such as

1315: 1060: 159: 51: 2074: 1699: 1441:

National Pipe Taper Fuel (NPTF), also known as Dryseal, a better sealing version of NPT.

2649: 2542: 2285: 2253: 2043: 1890: 1802: 1536: 1071: 934: 704:

As the distance from the crest of one thread to the next, pitch can be compared to the

595: 490: 2604: 2585: 2569: 2561: 2552: 2530: 2520: 2495: 2476: 2241: 2231: 2207: 1867: 1762: 1497: 1485:(BSP) which exists in a taper and non taper variant; used for other purposes as well 1307: 1092: 765: 466: 381: 71: 2516: 2402: 2160: 2048: 1898: 1790: 1740:

was being compiled, they were either still in development or just newly introduced.

1578: 1562: 1531: 1287: 1087:

and friction, is classified (categorized) in thread standards. Achieving a certain

1043:, as ISO standards call them, are provided for in various degrees in corresponding 629: 571:

The included angle characteristic of the cross-sectional shape is often called the

1668: 1119:

is a standard used for classifying the tolerance of the thread pitch diameter for

1039:

and to expedite hand assembly up to the length of engagement. Such allowances, or

2654: 2470: 2105: 2018: 1882: 1798: 1729: 1683: 1541: 1348: 1088: 510: 429: 362:

In some gas supply connections to prevent dangerous misconnections, for example:

185:

https://en.wikipedia.org/search/?title=Screw_thread&action=edit&section=1

122: 55: 27:

Helical structure used to convert between rotational and linear movement or force

2629: 2275:, 2007-03-05, Version 1.3. Table 3: The market share of each screw thread, p. 7. 1418:

Unified Coarse (UNC), the successor to the obsolete National Coarse (NC) thread.

905: 780:) include a coarse pitch and a fine pitch for each major diameter. For example, 661:

is the distance from the crest of one thread to the next one at the same point.

521: 445: 147:

Moving objects linearly by converting rotary motion to linear motion, as in the

2023: 1844: 1783: 1774: 1610: 1311: 725:

This distinction is analogous to that between coarse teeth and fine teeth on a

576: 118: 2634: 1330: 1243: 1091:

requires the ability to work within tolerance ranges for dimension (size) and

263:

The helix of a thread can twist in two possible directions, which is known as

2643: 2624: 2534: 2008: 1921: 1851: 1661: 1270: 402: 388: 316: 306: 152: 133: 129: 2245: 1720:

Graphic representation of formulas for the pitches of threads of screw bolts

1421:

Unified Fine (UNF), the successor to the obsolete National Fine (NF) thread.

832: 343:

heads, so that the torque tends to tighten rather than loosen the connection

2038: 1860: 1840: 1806: 1732:, New York and London, McGraw-Hill, pp. 16–22. USS, metric, Whitworth, and 824: 566: 554: 536: 409: 373: 340: 114: 514: 247: 229:. Assembling a male-threaded fastener to a female-threaded one is called 2033: 1905: 1878: 1674: 1525: 1236: 1120: 730: 433: 426: 418: 1055:

The pitch diameter of external threads is measured by various methods:

412:

for the blade to move in the direction of a regulating right hand finger

1993: 1507: 1303: 1263: 910: 705: 550: 356: 255: 173:

In all of these applications, the screw thread has two main functions:

142: 110: 35: 408:

The depth of cut screw of a "Bailey" (or "Stanley-Bailey") type metal

30: 1614: 1291: 734: 713: 670: 557:

use conventional thread forms and threaded rollers instead of balls.

474: 369: 347: 268: 242: 148: 2565: 2456:

Wilson pp. 77–78 (page numbers may be from an earlier edition).

1856: 1765:

standards (including screw size standards), reported in the journal

1716: 619:

Up to four starts are labeled with different colors in this example.

2127:"Threaded stud / steel / clamping – S&W Manufacturing Co., Inc" 1605:-inch BSW (not common in the US, but used in the rest of the world) 1593:-inch BSW (not common in the US, but used in the rest of the world) 1409:

ANSI/ASME B1.1 Unified Inch Screw Threads, (UN and UNR Thread Form)

505:. For 60° V-threads, the isosceles triangle is, more specifically, 470: 86: 1617:

have reverted to the BSW threads, or have never fully converted):

1242:

This additional truncation is achieved by using a slightly larger

34:

Screw thread, used to convert torque into the linear force in the

1961: 1581:(TPI) Unified Special thread (UNS, USA and the rest of the world) 773: 611:

for two screw threads; one with one start and one with two starts

600: 322: 310: 2556: 1356: 545:

The point of the threadform adds little strength to the thread.

329: 1908:. In 1947, the ISO was founded; and in 1960, the metric-based 638: 1411:. In some cases products are still made according to the old 845: 837: 222: 180:

It prevents linear motion without the corresponding rotation.

166: 47: 1877:

A tremendous amount of engineering work was done throughout

790:-13 belongs to the UNC series (Unified National Coarse) and 1186:

The nominal diameter of Metric (e.g. M8) and Unified (e.g.

709: 1696:(ANSI/ASME B1.20.7-1991 ) for garden hoses and accessories 1095:. Defining and achieving classes of fit are important for 587:"Threads per inch" redirects here. For woven fabrics, see 453:

The cross-sectional shape of a thread is often called its

283:. Threads oriented in the opposite direction are known as 2568:); and by Lindsay Publications, Inc., Bradley, Illinois ( 2490:

Degarmo, E. Paul; Black, J T.; Kohser, Ronald A. (2003),

1302:

The screw thread concept seems to have occurred first to

1083:

The way in which male and female fit together, including

726: 532:

The cutting or forming tool's edge will break too easily;

328:

The securing nut on some circular saw blades – the large

2508: 1906:

metric system was eclipsing inch-based measurement units

1048:

possible due to the margin of tolerance. A class called

2560:. Reprinted by McGraw-Hill, New York and London, 1926 ( 1702:, a German metric thread used for measuring instruments 553:, the male-female pairs have bearing balls in between. 421:

lamps and fittings (such as those formerly used on the

66:

thread. A screw thread is the essential feature of the

58:

in the form of a helix, with the former being called a

2286:"American National Standard vs. Unified Inch Standard" 384:

will have one right-handed and one left-handed thread.

691:-20 thread has 20 TPI, which means that its pitch is 502: 1522:

threads (GPI), primarily for glass bottles and vials

807:

here does not mean lower quality, nor does the term

641: 635: 664:Because the vast majority of screw threadforms are 632: 2489: 1464:(BSW), and for other Whitworth threads including: 868:, in ISO terminology), and the maximum limits for 398:In mechanisms to give a more intuitive action as: 2551:, New Haven, Connecticut: Yale University Press, 575:. For most V-threads, this is standardized as 60 2641: 2417: 1503:British Standard Buttress Threads (BS 1657:1950) 754:-20 UNC (left, for aluminium cylinder head) and 589:Units of textile measurement § Thread count 2079:. John Wiley & sons, Incorporated. p. 1669:http://www.fahrradmonteur.de/fahrradgewinde.php 535:The part or fastener's thread crests will have 2437: 2435: 2206:(25 ed.). Industrial Press. p. 893. 1435:, used in North America for several purposes. 1386:International Organization for Standardization 2584:(23rd ed.), New York: Industrial Press, 2372: 1843:, but like Whitworth etc. were defined using 1711: 1074:may also be used to determine PD graphically. 828:The three diameters that characterize threads 391:, to provide a "secret" method of disassembly 177:It converts rotary motion into linear motion. 2363: 1290:, or a liquid or paste pipe sealant such as 764:-28 UNF (right, for steel nut; from a 1960s 489:Most triangular threadforms are based on an 2432: 2266: 1978:Threading (manufacturing) § Inspection 1456:National Pipe Straight Hose coupling (NPSH) 1444:National Pipe Taper Railing fittings (NPTR) 2343: 2305: 1391: 844:There are three characteristic diameters ( 733:, or between coarse grit and fine grit on 582: 355:In combination with right-hand threads in 1827:National Coarse (NC), National Fine (NF), 1786:was one of those whom history has noted. 332:at startup should tend to tighten the nut 102:Screw threads have several applications: 2492:Materials and Processes in Manufacturing 2468: 1756: 1743: 1723: 1715: 1652:Aerospace metric threads (MJ) – ISO 5855 1450:National Pipe Straight Mechanical (NPSM) 1329: 979:away from it, the "PD line," slices the 956: 904: 831: 823: 739: 614: 599: 444: 254: 246: 29: 2072: 1496:(BA), primarily electronic/electrical, 1373:The most common threads in use are the 1362: 1024:away from the position of the PD line. 136:to each other and to caps and fixtures. 14: 2642: 2598: 2580:Ryffel, Henry H.; et al. (1988), 2579: 2331: 2153: 1964:to follow the other processes); newer 1935: 1447:National Pipe Straight Coupling (NPSC) 701:inch (0.050 in or 1.27 mm). 401:The leadscrew of the cross slide of a 2346:"Sewing Machine Thread (Nähnorm 100)" 2201: 1868:Society of Automobile Engineers (SAE) 1730:American Machinists' Handbook, 2nd ed 1658:Metal bone screws (HA, HB) – ISO 5835 1646:Tapping screw threads (ST) – ISO 1478 1453:National Pipe Straight Locknut (NPSL) 1154: 719: 387:In some instances, for example early 2179:"Identifying threads and connectors" 2171: 1866:Sometime between 1912 and 1916, the 1473:Cycle Engineers' Institute (CEI) or 1160: 1102: 917:. Only the commonly used values for 520:The theoretical triangle is usually 325:on the left side of some automobiles 259:The right-hand rule of screw threads 251:Right- and left-handed screw threads 2635:NASA RP-1228 Fastener Design Manual 2601:Design Dimensioning and Tolerancing 2541: 2441: 2423: 2378: 1932:terminology is not always precise. 1887:production thread-grinding machines 1251: 1247: 24: 2603:(4th ed.), Goodheart-Wilcox, 2548:English and American Tool Builders 1488:British Standard Pipe Taper (BSPT) 1325: 201:Gender of connectors and fasteners 25: 2671: 2618: 2195: 2161:"Coarse Threads vs. Fine Threads" 2100: 1837:British Association screw threads 1655:Tyre valve threads (V) – ISO 4570 1494:British Association screw threads 1413:American National Standard Series 1078: 952: 928:differ between the two standards. 900: 879: 321:The axle nuts, or less commonly, 279:) thread, because it follows the 81:of a screw thread depends on its 2344:www.mipraso.de, Michael Prandl. 2306:www.mipraso.de, Michael Prandl. 1947: 1641:-inch BSW for heavier luminaires 1629:-inch BSW for lighter luminaires 1516:a fixed pitch 26 TPI thread 628: 2450: 2387: 2337: 2325: 2299: 2278: 2073:Burnham, Reuben Wesley (1915). 1384:These were standardized by the 1166: 1107: 772:The common V-thread standards ( 205:Every matched pair of threads, 97: 62:thread and the latter called a 2625:International Thread Standards 2220: 2144: 2119: 2094: 2066: 1904:However, internationally, the 1750:Mechanical Engineers' Handbook 13: 1: 2462: 2090:– via Internet Archive. 2014:Metric: M Profile Thread Form 1971: 1910:International System of Units 1823:United States Standard thread 1777:around 1800, when the modern 1761:Survey results on the use of 941:radial movement. The reduced 744:Camshaft cover stud threaded 477:, or other shapes. The terms 315:The left grinding wheel on a 236: 1968:; and combinations thereof. 1551:(RMS) thread, also known as 1483:British standard pipe thread 1359:(wrenches) and other tools. 893:of the bolt threads and the 819: 716:are inverses of each other. 501:because of the shape of the 7: 2515:(25th ed.), New York: 2202:Green, Robert, ed. (1996). 1986: 1835:Meanwhile, in Britain, the 1694:Hose Coupling Screw Threads 1557:microscope objective lenses 1549:Royal Microscopical Society 1500:and to mount optical lenses 1377:(M) for most purposes, and 965:The pitch diameter (PD, or 913:is the same as that of all 493:. These are usually called 300:fretting induced precession 10: 2676: 2630:ModelFixings – Thread Data 2472:Design of Machine Elements 2076:Mathematics for Machinists 1975: 1951: 1831:National Pipe Taper (NPT). 1795:British Standard Whitworth 1712:History of standardization 1462:British Standard Whitworth 1366: 1341: 1297: 1161:Standardization of threads 593: 586: 564: 240: 198: 2660:Threading (manufacturing) 2599:Wilson, Bruce A. (2004), 2106:"Bicycle Glossary: Pedal" 2004:Dryseal Pipe Threads Form 1954:Threading (manufacturing) 1801:presented a paper to the 1520:Glass Packaging Institute 1438:National Pipe Taper (NPT) 1424:Unified Extra Fine (UNEF) 1338:, ISO metric screw thread 909:The basic profile of all 194: 189: 68:screw as a simple machine 2060: 1815:Baldwin Locomotive Works 1375:ISO metric screw threads 1344:List of thread standards 1257: 915:ISO metric screw threads 560: 2494:(9th ed.), Wiley, 2273:ISO/TC/ 1 Business Plan 1895:Unified Thread Standard 1678:Incandescent light bulb 1405:Unified Thread Standard 1392:Other current standards 1369:ISO metric screw thread 1181:trigonometric functions 778:Unified Thread Standard 583:Lead, pitch, and starts 440: 350:and floor standing fans 2469:Bhandari, V B (2007), 2258:: CS1 maint: others ( 2131:www.directindustry.com 1999:British Standard Cycle 1770: 1754: 1741: 1721: 1514:British Standard Brass 1475:British Standard Cycle 1398:backward compatibility 1339: 1041:fundamental deviations 962: 929: 841: 840:in a technical drawing 829: 769: 620: 612: 450: 260: 252: 213:, can be described as 39: 2350:www.gewinde-normen.de 2312:www.gewinde-normen.de 1918:Système International 1819:Pennsylvania Railroad 1760: 1747: 1727: 1719: 1706:Sewing machine thread 1506:British Standard for 1468:British Standard Fine 1427:Unified Special (UNS) 1333: 1320:Industrial Revolution 960: 908: 835: 827: 743: 618: 603: 448: 432:rolling stock of the 258: 250: 33: 2582:Machinery's Handbook 2512:Machinery's Handbook 2475:, Tata McGraw-Hill, 2228:Engineering graphics 2204:Machinery's Handbook 2054:Thread-locking fluid 2019:National Thread Form 1942:engineering drawings 1684:Fire hose connection 1433:National pipe thread 1363:ISO standard threads 1163:is discussed below. 1117:pitch diameter limit 1059:A dedicated type of 714:period and frequency 423:New York City Subway 302:. Examples include: 281:right-hand grip rule 79:mechanical advantage 2543:Roe, Joseph Wickham 2183:Essentra Components 1994:Anti-seize compound 1966:additive techniques 1936:Engineering drawing 1926:automotive industry 1891:optical comparators 1779:screw-cutting lathe 1680:holder screw thread 1316:screw-cutting lathe 1277:. Examples are the 141:Gear reduction via 92:elastic deformation 2308:"Löwenherz Thread" 2044:Thread pitch gauge 1881:and the following 1803:Franklin Institute 1771: 1755: 1742: 1722: 1537:Square thread form 1498:moving coil meters 1381:(R, G) for pipes. 1340: 1155:Interchangeability 1097:interchangeability 1072:optical comparator 963: 943:material condition 935:optical comparator 930: 842: 830: 770: 720:Coarse versus fine 621: 613: 596:Lead (engineering) 513:, the triangle is 491:isosceles triangle 451: 359:and clamping studs 261: 253: 113:, plastic screws, 109:Fasteners such as 40: 2591:978-0-8311-1200-4 2574:978-0-917914-73-7 2526:978-0-8311-2575-2 2482:978-0-07-061141-2 2150:Bhandari, p. 205. 1563:Microphone stands 1308:Leonardo da Vinci 1103:Tolerance classes 72:threaded fastener 16:(Redirected from 2667: 2613: 2595: 2559: 2538: 2517:Industrial Press 2505: 2485: 2457: 2454: 2448: 2439: 2430: 2421: 2415: 2414: 2412: 2410: 2401:. Archived from 2391: 2385: 2376: 2370: 2367: 2361: 2360: 2358: 2356: 2341: 2335: 2329: 2323: 2322: 2320: 2318: 2303: 2297: 2296: 2294: 2292: 2282: 2276: 2270: 2264: 2263: 2257: 2249: 2224: 2218: 2217: 2199: 2193: 2192: 2190: 2189: 2175: 2169: 2168: 2157: 2151: 2148: 2142: 2141: 2139: 2137: 2123: 2117: 2116: 2114: 2113: 2098: 2092: 2091: 2089: 2087: 2070: 2049:Thread protector 1916:from the French 1899:Washington, D.C. 1791:Joseph Whitworth 1700:Löwenherz thread 1640: 1639: 1635: 1628: 1627: 1623: 1604: 1603: 1599: 1592: 1591: 1587: 1579:threads per inch 1576: 1575: 1571: 1532:Acme thread form 1288:thread seal tape 1275:slightly conical 1216: 1215: 1211: 1205: 1204: 1200: 1195: 1194: 1190: 1150: 1146: 1142: 1139: 1138: 1134: 1050:interference fit 799: 798: 794: 789: 788: 784: 766:Jaguar XK engine 763: 762: 758: 753: 752: 748: 700: 699: 695: 690: 689: 685: 679:threads per inch 648: 647: 644: 643: 640: 637: 634: 511:buttress threads 21: 2675: 2674: 2670: 2669: 2668: 2666: 2665: 2664: 2640: 2639: 2621: 2611: 2592: 2527: 2502: 2483: 2465: 2460: 2455: 2451: 2440: 2433: 2422: 2418: 2408: 2406: 2405:on 13 June 2005 2393: 2392: 2388: 2377: 2373: 2368: 2364: 2354: 2352: 2342: 2338: 2334:, p. 1603. 2330: 2326: 2316: 2314: 2304: 2300: 2290: 2288: 2284: 2283: 2279: 2271: 2267: 2251: 2250: 2238: 2226: 2225: 2221: 2214: 2200: 2196: 2187: 2185: 2177: 2176: 2172: 2159: 2158: 2154: 2149: 2145: 2135: 2133: 2125: 2124: 2120: 2111: 2109: 2108:. Sheldon Brown 2099: 2095: 2085: 2083: 2071: 2067: 2063: 2058: 1989: 1980: 1974: 1956: 1950: 1938: 1883:interwar period 1799:William Sellers 1714: 1637: 1633: 1632: 1625: 1621: 1620: 1601: 1597: 1596: 1589: 1585: 1584: 1573: 1569: 1568: 1542:Buttress thread 1394: 1371: 1365: 1349:Standardization 1346: 1328: 1326:Standardization 1300: 1260: 1213: 1209: 1208: 1202: 1198: 1197: 1192: 1188: 1187: 1169: 1157: 1148: 1144: 1140: 1136: 1132: 1131: 1110: 1105: 1081: 1023: 1012: 1001: 994: 978: 971: 955: 923: 903: 882: 822: 796: 792: 791: 786: 782: 781: 760: 756: 755: 750: 746: 745: 722: 697: 693: 692: 687: 683: 682: 631: 627: 598: 592: 585: 569: 563: 443: 430:Sprague-Thomson 335:The spindle on 307:left foot pedal 245: 239: 203: 197: 192: 100: 28: 23: 22: 15: 12: 11: 5: 2673: 2663: 2662: 2657: 2652: 2638: 2637: 2632: 2627: 2620: 2619:External links 2617: 2616: 2615: 2609: 2596: 2590: 2577: 2539: 2525: 2506: 2500: 2487: 2481: 2464: 2461: 2459: 2458: 2449: 2431: 2416: 2386: 2371: 2362: 2336: 2324: 2298: 2277: 2265: 2236: 2219: 2212: 2194: 2170: 2152: 2143: 2118: 2102:Brown, Sheldon 2093: 2064: 2062: 2059: 2057: 2056: 2051: 2046: 2041: 2036: 2031: 2029:Tapered thread 2026: 2024:Nut (hardware) 2021: 2016: 2011: 2006: 2001: 1996: 1990: 1988: 1985: 1976:Main article: 1973: 1970: 1952:Main article: 1949: 1946: 1937: 1934: 1845:Imperial units 1784:Joseph Clement 1775:Henry Maudslay 1713: 1710: 1709: 1708: 1703: 1697: 1691: 1681: 1672: 1665: 1659: 1656: 1653: 1650: 1647: 1644: 1643: 1642: 1630: 1611:Stage lighting 1608: 1607: 1606: 1594: 1582: 1560: 1553:society thread 1546: 1545: 1544: 1539: 1534: 1523: 1517: 1511: 1504: 1501: 1491: 1490: 1489: 1480: 1479: 1478: 1471: 1459: 1458: 1457: 1454: 1451: 1448: 1445: 1442: 1439: 1430: 1429: 1428: 1425: 1422: 1419: 1393: 1390: 1367:Main article: 1364: 1361: 1342:Main article: 1334:An example of 1327: 1324: 1299: 1296: 1271:threaded pipes 1259: 1256: 1252:pitch diameter 1248:major diameter 1168: 1165: 1156: 1153: 1109: 1106: 1104: 1101: 1093:surface finish 1080: 1079:Classes of fit 1077: 1076: 1075: 1068: 1064: 1021: 1010: 999: 992: 976: 969: 954: 953:Pitch diameter 951: 921: 902: 901:Minor diameter 899: 881: 880:Major diameter 878: 858:pitch diameter 854:minor diameter 850:major diameter 848:) of threads: 821: 818: 721: 718: 594:Main article: 584: 581: 565:Main article: 562: 559: 547: 546: 543: 540: 533: 526:sharp V-thread 461:(also spelled 442: 439: 438: 437: 415: 414: 413: 406: 396: 392: 389:ballpoint pens 385: 378: 377: 376: 366: 360: 353: 352: 351: 344: 333: 326: 319: 313: 241:Main article: 238: 235: 199:Main article: 196: 193: 191: 188: 182: 181: 178: 171: 170: 163: 156: 145: 139: 138: 137: 130:threaded pipes 126: 115:machine screws 99: 96: 70:and also as a 26: 9: 6: 4: 3: 2: 2672: 2661: 2658: 2656: 2653: 2651: 2648: 2647: 2645: 2636: 2633: 2631: 2628: 2626: 2623: 2622: 2612: 2610:1-59070-328-6 2606: 2602: 2597: 2593: 2587: 2583: 2578: 2575: 2571: 2567: 2563: 2558: 2554: 2550: 2549: 2544: 2540: 2536: 2532: 2528: 2522: 2518: 2514: 2513: 2507: 2503: 2501:0-471-65653-4 2497: 2493: 2488: 2484: 2478: 2474: 2473: 2467: 2466: 2453: 2447: 2443: 2438: 2436: 2429: 2425: 2420: 2404: 2400: 2396: 2390: 2384: 2380: 2375: 2366: 2351: 2347: 2340: 2333: 2328: 2313: 2309: 2302: 2287: 2281: 2274: 2269: 2261: 2255: 2247: 2243: 2239: 2233: 2229: 2223: 2215: 2213:0-8311-2575-6 2209: 2205: 2198: 2184: 2180: 2174: 2166: 2162: 2156: 2147: 2132: 2128: 2122: 2107: 2103: 2097: 2082: 2078: 2077: 2069: 2065: 2055: 2052: 2050: 2047: 2045: 2042: 2040: 2037: 2035: 2032: 2030: 2027: 2025: 2022: 2020: 2017: 2015: 2012: 2010: 2009:Filter thread 2007: 2005: 2002: 2000: 1997: 1995: 1992: 1991: 1984: 1979: 1969: 1967: 1963: 1958: 1955: 1948:Manufacturing 1945: 1943: 1933: 1929: 1927: 1923: 1922:Globalization 1919: 1915: 1912:(abbreviated 1911: 1907: 1902: 1900: 1896: 1892: 1888: 1884: 1880: 1875: 1871: 1869: 1864: 1862: 1858: 1853: 1848: 1846: 1842: 1838: 1833: 1832: 1828: 1824: 1820: 1816: 1810: 1808: 1804: 1800: 1796: 1792: 1787: 1785: 1780: 1776: 1768: 1767:Horseless Age 1764: 1759: 1751: 1746: 1739: 1735: 1731: 1726: 1718: 1707: 1704: 1701: 1698: 1695: 1692: 1690:standard 194) 1689: 1685: 1682: 1679: 1676: 1673: 1670: 1666: 1663: 1662:Panzergewinde 1660: 1657: 1654: 1651: 1648: 1645: 1631: 1619: 1618: 1616: 1612: 1609: 1595: 1583: 1580: 1567: 1566: 1564: 1561: 1558: 1554: 1550: 1547: 1543: 1540: 1538: 1535: 1533: 1530: 1529: 1527: 1524: 1521: 1518: 1515: 1512: 1509: 1505: 1502: 1499: 1495: 1492: 1487: 1486: 1484: 1481: 1476: 1472: 1469: 1466: 1465: 1463: 1460: 1455: 1452: 1449: 1446: 1443: 1440: 1437: 1436: 1434: 1431: 1426: 1423: 1420: 1417: 1416: 1414: 1410: 1406: 1403: 1402: 1401: 1399: 1389: 1387: 1382: 1380: 1376: 1370: 1360: 1358: 1353: 1350: 1345: 1337: 1332: 1323: 1321: 1317: 1314:invented the 1313: 1309: 1305: 1295: 1293: 1289: 1284: 1280: 1276: 1272: 1267: 1265: 1255: 1253: 1249: 1245: 1240: 1238: 1234: 1229: 1227: 1223: 1219: 1184: 1182: 1176: 1174: 1164: 1162: 1152: 1128: 1126: 1122: 1118: 1114: 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It may be 464: 460: 456: 447: 435: 431: 428: 424: 420: 416: 411: 407: 404: 400: 399: 397: 393: 390: 386: 383: 379: 375: 374:LPG cylinders 371: 367: 364: 363: 361: 358: 354: 349: 345: 342: 338: 334: 331: 327: 324: 320: 318: 317:bench grinder 314: 312: 308: 304: 303: 301: 297: 296: 295: 292: 290: 286: 282: 278: 274: 270: 266: 257: 249: 244: 234: 232: 228: 224: 220: 216: 212: 208: 202: 187: 186: 179: 176: 175: 174: 168: 164: 161: 157: 154: 150: 146: 144: 140: 135: 131: 127: 124: 120: 116: 112: 108: 107: 105: 104: 103: 95: 93: 88: 84: 80: 75: 73: 69: 65: 61: 57: 53: 49: 45: 37: 32: 19: 2600: 2581: 2547: 2510: 2491: 2471: 2452: 2428:pp. 248–249. 2419: 2407:. Retrieved 2403:the original 2398: 2389: 2374: 2365: 2353:. Retrieved 2349: 2339: 2327: 2315:. Retrieved 2311: 2301: 2289:. Retrieved 2280: 2268: 2227: 2222: 2203: 2197: 2186:. Retrieved 2182: 2173: 2164: 2155: 2146: 2134:. Retrieved 2130: 2121: 2110:. Retrieved 2096: 2084:. Retrieved 2075: 2068: 2039:Thread angle 1981: 1959: 1957: 1940:In American 1939: 1930: 1917: 1913: 1903: 1876: 1872: 1865: 1861:capital cost 1849: 1841:Thury thread 1834: 1830: 1826: 1811: 1807:Philadelphia 1788: 1772: 1766: 1749: 1737: 1552: 1412: 1395: 1383: 1372: 1354: 1347: 1335: 1301: 1268: 1261: 1241: 1232: 1230: 1225: 1221: 1217: 1185: 1177: 1173:thread depth 1172: 1170: 1167:Thread depth 1158: 1129: 1124: 1116: 1113:Thread limit 1112: 1111: 1108:Thread limit 1089:class of fit 1082: 1054: 1049: 1044: 1040: 1037:interference 1036: 1032: 1030: 1026: 1018: 1014: 1007: 1003: 996: 989: 985: 980: 973: 966: 964: 947: 942: 939: 931: 925: 918: 894: 890: 887: 883: 873: 869: 865: 861: 857: 853: 849: 843: 814: 808: 804: 802: 771: 723: 703: 678: 675: 666:single-start 665: 663: 658: 654: 650: 623: 622: 608: 604: 573:thread angle 572: 570: 567:Thread angle 548: 525: 519: 498: 494: 488: 482: 478: 462: 458: 454: 452: 410:plane (tool) 341:line trimmer 293: 288: 284: 276: 273:right-handed 272: 264: 262: 230: 226: 218: 214: 210: 206: 204: 183: 172: 101: 98:Applications 82: 76: 63: 59: 44:screw thread 43: 41: 18:Thread pitch 2332:Ryffel 1988 2165:katonet.com 2034:Tap and die 1879:World War I 1675:Edison base 1526:Power screw 1508:Spark Plugs 1379:BSP threads 1237:tap and die 1143:in = 0.0625 911:UTS threads 551:ball screws 507:equilateral 499:vee-threads 475:trapezoidal 463:thread form 434:Paris Metro 427:World War I 425:or the pre- 419:Edison base 357:turnbuckles 337:brushcutter 285:left-handed 143:worm drives 128:Connecting 111:wood screws 106:Fastening: 2644:Categories 2463:References 2237:0023427604 2188:2021-03-05 2112:2010-10-19 1972:Inspection 1510:BS 45:1972 1304:Archimedes 1264:wood screw 1061:micrometer 706:wavelength 483:threadform 471:triangular 459:threadform 348:table fans 265:handedness 237:Handedness 160:micrometer 36:flood gate 2650:Fasteners 2535:473691581 2383:pp. 9–10. 2254:cite book 1789:In 1841, 1615:Australia 1577:-inch 27 1292:pipe dope 1244:tap drill 1033:allowance 820:Diameters 803:The term 735:sandpaper 671:parameter 522:truncated 495:V-threads 370:POL valve 269:clockwise 243:Chirality 149:leadscrew 2566:27-24075 2557:16011753 2545:(1916), 2442:Roe 1916 2424:Roe 1916 2399:asme.org 2379:Roe 1916 2246:13498926 1987:See also 1817:and the 1738:Handbook 1528:threads 1357:spanners 1220:or 0.125 1006:, & 870:internal 862:external 503:letter V 395:threaded 382:coupling 323:lug nuts 211:internal 207:external 87:friction 60:straight 52:cylinder 2446:p. 249. 2409:4 April 2355:4 April 2317:4 April 2136:4 April 2086:4 April 1962:lapping 1636:⁄ 1624:⁄ 1600:⁄ 1588:⁄ 1572:⁄ 1298:History 1212:⁄ 1201:⁄ 1191:⁄ 1135:⁄ 1045:classes 981:sharp-V 795:⁄ 785:⁄ 774:ISO 261 759:⁄ 749:⁄ 696:⁄ 686:⁄ 577:degrees 515:scalene 311:bicycle 64:tapered 48:helical 2655:Screws 2607: 2588: 2572: 2564: 2555: 2533: 2523: 2498: 2479: 2291:14 Mar 2244: 2234: 2210: 1857:Zürich 1852:metric 1769:, 1916 1312:Besson 1149: 1145: 1141: 856:, and 805:coarse 649:) and 509:. 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