■ for Whitworth Threads ■ for Sewing Machine Screw Threads

Unit:mm Unit:mm

MajorPitch DiameterMinorMajorPitch DiameterMinor
DiameterDiameterDiameterDiameter

Size Class Upper Lower Size Class Upper Lower

BasicBasicTolerance ToleranceBasicBasicBasicTolerance ToleranceBasic
SizeSize( μ m)( μ m)SizeSizeSize( μ m)( μ m)Size
1/8 W 40P13.1752.76825102.3621/16 SM 80P11.5881.38225101.176
5/32W 32P23.9693.46040202.9525/64 SM 64P11.9841.72625101.468
3/16 W 24P24.7624.08540203.4073/32 SM 56P12.3812.08625101.791
7/32 W 24P25.5564.87940204.2013/32 SM 100P12.3812.21625102.051
1/4 W 20P26.3505.53740204.7241/8 SM 40P23.1752.76340252.351
5/16 W 18P27.9387.03440206.1301/8 SM 44P23.1752.80040252.425
3/8 W 16P29.5258.50940207.4939/64 SM 40P23.5723.16040252.748
7/16 W 14P311.1129.95060408.78811/64 SM 40P24.3663.95440253.542
1/2 W 12P312.700 11.34560409.9903/16 SM 24P24.7624.07540203.388
9/16 W 12P314.288 12.9336040 11.5783/16 SM 28P24.7624.17340203.584
5/8 W 11P315.875 14.3966040 12.9173/16 SM 32P24.7624.24640203.730
3/4 W 10P319.050 17.4246040 15.7983/16 SM 40P24.7624.35040253.938
7/8 W 9P322.225 20.4186040 18.6117/32 SM 32P25.5565.04040204.524
1 W 8P325.400 23.3676020 21.33415/64 SM 28P25.9535.36440204.775
1 1/8W 7P428.575 26.2528040 23.9291/4 SM 24P26.3505.66340204.976
1 1/4W 7P431.750 29.4278040 27.1041/4 SM 40P16.3505.93825105.526
1 3/8W 6P434.925 32.2148040 29.503
1 1/2W 6P438.100 35.3898040 32.678
1 5/8W 5P441.275 38.0228040 34.769
1 3/4W 5P444.450 41.1978040 37.944
1 7/8W 4 1/2P447.625 44.0118040 40.397
2 W 4 1/2P450.800 47.1868040 43.572

Technical Inf