Lister 5/1 Diesel

Threading Tables

Chart No 2 - British Standard Fine (BSF) Threads


British Standard Fine Threads (55 Deg Thread Angle)
Dimensions in Inches except where stated

Thread Form Data Tapping Drill Clearance Drill
Diameter O/Diameter Core Pitch Depth Radius Effective Dia T.P.I Dec / Met / Frac Dec / Met / Frac
3/16" 0.1875 0.1475 0.0312 0.0200 0.0046 0.1675 32 0.1562 - 5/32" 0.1929 - 4.90mm
7/32" 0.2188 0.1730 0.0357 0.0229 0.0049 0.1958 28 0.1831 - 4.65mm 0.2205 - 5.60mm
1/4" 0.2500 0.2008 0.0385 0.0246 0.0053 0.2254 26 0.2087 - 5.30mm 0.2559 - 6.50mm
5/16" 0.3125 0.2543 0.0454 0.0291 0.0062 0.2834 22 0.2657 - 6.75mm 0.3150 - 8.00mm
3/8" 0.3750 0.3110 0.0500 0.0320 0.0069 0.3430 20 0.3248 - 8.25mm 0.3858 - 9.80mm
7/16" 0.4375 0.3663 0.0555 0.0356 0.0076 0.4019 18 0.3819 - 9.70mm 0.4531 - 29/64"
1/2" 0.5000 0.4200 0.0625 0.0400 0.0086 0.4600 16 0.4375 - 7/16" 0.5156 - 35/64"
9/16" 0.5625 0.4825 0.0625 0.0400 0.0086 0.5225 16 0.5000 - 1/2" 0.5781 - 37/64"
5/8" 0.6250 0.5336 0.0714 0.0457 0.0098 0.5793 14 0.5512 - 14.00mm 0.6406 - 41/64"
3/4" 0.7500 0.6432 0.0833 0.0534 0.0114 0.6966 12 0.6594 - 16.75mm 0.7656 - 49/64"
7/8" 0.8750 0.7586 0.0909 0.0582 0.0125 0.8168 11 0.7812 - 25/32" 0.8906 - 57/64"
1" 1.0000 0.8720 0.1000 0.0640 0.0137 0.9360 10 0.8957 - 22.75mm 1.0156 - 1-1/64"
1-1/8" 1.1250 0.9828 0.1111 0.0711 0.0153 1.0539 9 1.0039 - 25.50mm 1.1406 - 1-9/64"
1-1/4" 1.2500 1.1078 0.1111 0.0711 0.0153 1.1789 9 1.1319 - 28.75 1.2656 - 1-17/64"
1-3/8" 1.3750 1.2150 0.1250 0.0800 0.0172 1.2950 8 1.2402 - 31.50 1.3906 - 1-25/64"
1-1/2" 1.5000 1.3400 0.1250 0.0800 0.0172 1.4200 8 1.3594 - 1-23/64" 1.5156 - 1-33/64"
1-5/8" 1.6250 1.4649 0.1250 0.0800 0.0172 1.5450 8 1-23/64" --
1-3/4" 1.7500 1.5670 0.1429 0.0915 0.0196 1.6585 7 1-19/32" --
2" 2.0000 1.8170 0.1429 0.0915 0.0196 1.9085 7 1-27/32" --
2-1/4" 2.250 2.0366 0.1666 0.1067 0.0229 2.1433 6 2-1/16" --
2-1/2" 2.500 2.2866 0.1666 0.1067 0.0229 2.3933 6 2-5/16" --
2-3/4" 2.750 2.5366 0.1666 0.1067 0.0229 2.6433 6 2-9/16" --
3" 3.0000 2.7439 0.2000 0.1280 0.0275 2.8719 5 2-3/4" --


Main Mechanical Menu