WHITWORTH SCREW THREAD

Diagram of the Whitworth screw thread

tablas, calculos, taller

Abbreviations:

P = Pitch in mm.

N = Number of threads per inch.

H = Height.

r = Radius

D = Depth.

DE = Screw Diameter.

DM = Mid Diameter.

DF = Interior Diameter.

Formulas and Calculator:

P = 25,4 / N
= 25,4 /
D = 0,6403 * P
= 0,6403 *
D = 16,256 / N
= 16,256 /
H = 0,9605 * P
= 0,9605 *
H = 24,384 / N
= 24,384 /
r = 0,1373 * P
= 0,1373 *
DM = (DE + DF)/2
= ( + ) / 2
DM = DE - D
= -
DM = DE - (16,256 / N)
= - (16,256 / )
DF = DE - (1,28 * P)
= - (1,28 * )
DF = DE - (32,512 / N)
= - (32,512 / )

Whitworth thread sizes table

Major
diameter
Thread
pitch
Minor
diameter
75% tap
drill size
(in) (mm) (in−1) (mm) (in) (mm) (in) (mm)
116 1.588 60 0.423 0.0412 1.046 #56 1.2
332 2.381 48 0.529 0.0671 1.704 #49 1.9
18 3.175 40 0.635 0.0930 2.362 #39 2.6
532 3.969 32 0.794 0.1162 2.951 #30 3.2
316 4.763 24 1.058 0.1341 3.406 #26 3.7
732 5.556 24 1.058 0.1654 4.201 #16 4.5
14 6.350 20 1.270 0.1860 4.724 #9 5.1
516 7.938 18 1.411 0.2414 6.132 F 6.6
38 9.525 16 1.588 0.2950 7.493 516 8.0
716 11.113 14 1.814 0.3460 8.788 U 9.4
12 12.700 12 2.117 0.3933 9.990 2764 10.7
916 14.288 12 2.117 0.4558 11.577 3164 12.3
58 15.875 11 2.309 0.5086 12.918 1732 13.7
1116 17.463 11 2.309 0.5711 14.506 1932 15.2
34 19.050 10 2.540 0.6219 15.796 2132 16.6
1316 20.638 10 2.540 0.6844 17.384 2332 18.2
78 22.225 9 2.822 0.7327 18.611 4964 19.5
1516 23.813 9 2.822 0.7952 20.198 5364 21.1
1 25.400 8 3.175 0.8399 21.333 78 22.3
118 28.575 7 3.629 0.9420 23.927 6364 25.1
114 31.750 7 3.629 1.0670 27.102 1764 28.3
138 34.925 6 4.233 1.1616 29.505 1732 30.9
112 38.100 6 4.233 1.2866 32.680 1516 34.0
158 41.275 5 5.080 1.3689 34.770 1716 36.4
134 44.450 5 5.080 1.4939 37.945 1916 39.6
178 47.625 412 5.644 1.5904 40.396 158 42.2
2 50.800 412 5.644 1.7154 43.571 134 45.4
218 53.975 412 5.644 1.8404 46.746 178 48.6
214 57.150 4 6.350 1.9298 49.017 2 51.1
238 60.325 4 6.350 2.0548 52.192 218 54.2
212 63.500 4 6.350 2.1798 55.367 214 57.4
258 66.675 4 6.350 2.3048 58.542 238 60.6
234 69.850 312 7.257 2.3841 60.556 212 62.9
278 73.025 312 7.257 2.5091 63.731 258 66.1
3 76.200 312 7.257 2.6341 66.906 234 69.2
314 82.550 314 7.815 2.8560 72.542 3 75.0
312 88.900 314 7.815 3.1060 78.892 314 81.4
334 95.250 3 8.467 3.3231 84.407 338 87.1
4 101.600 3 8.467 3.5731 90.757 358 93.5
414 107.950 278 8.835 3.8046 96.637 378 99.5
412 114.300 278 8.835 4.0546 102.987 418 105.8
434 120.650 234 9.236 4.2843 108.821 438 111.8
5 127.000 234 9.236 4.5343 115.171 458 118.1
514 133.350 258 9.676 4.7621 120.957 478 124.1
512 139.700 258 9.676 5.0121 127.307 518 130.4
534 146.050 212 10.160 5.2377 133.038 538 136.3
6 152.400 212 10.160 5.4877 139.388 558 142.6

Hex head sizes table

Size BS 190 BS 1083 DIN
(in) (in) (mm) (in) (mm) (mm)
18 0.344 8.7
316 0.445 11.3
14 0.525 13.3 0.445 11.3 11
516 0.600 15.2 0.525 13.3 14
38 0.710 18.0 0.600 15.2 17
716 0.820 20.8 0.710 18.0 19
12 0.920 23.4 0.820 20.8 22
916 1.010 25.7 0.920 23.4
58 1.100 27.9 1.010 25.7 27
34 1.300 33.0 1.200 30.5 32
78 1.480 37.6 1.300 33.0 36
1 1.670 42.4 1.480 37.6 41
118 1.860 47.2 1.670 42.4
114 2.050 52.1 1.860 47.2
138 2.050 52.1
112 2.410 61.2 2.220 56.4
134 2.760 70.1 2.580 65.5
2 3.150 80.0 2.760 70.1

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