Lister 5/1 Diesel

Threading Tables

Chart No 1 - Whitworth Threads


Whitworth Form 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
1/8" 0.1250 0.0930 0.0250 0.0160 0.0034 0.1090 40 0.1004 - 2.55mm 0.1299 - 3.30mm
3/16" 0.1875 0.1341 0.0417 0.0267 0.0057 0.1608 24 0.1457 - 3.70mm 0.1968 - 5.00mm
1/4" 0.2500 0.1860 0.0500 0.0320 0.0069 0.2180 20 0.2008 - 5.10mm 0.2559 - 6.50mm
5/16" 0.3125 0.2414 0.0556 0.0076 0.0076 0.2769 18 0.2559 - 6.50mm 0.3150 - 8.00mm
3/8" 0.3750 0.2950 0.0625 0.0400 0.0086 0.3350 16 0.3125 - 5/16" 0.3858 - 9.80mm
7/16" 0.4375 0.3460 0.0714 0.0457 0.0098 0.3918 14 0.3642 - 9.25mm 0.4531 - 29/64"
1/2" 0.5000 0.3933 0.0833 0.0534 0.0114 0.4466 12 0.4134 - 10.50mm 0.5156 - 33/64"
9/16" 0.5625 0.4558 0.0833 0.0534 0.0114 0.5091 12 0.4764 - 12.10mm 0.5781 - 37/64"
5/8" 0.6250 0.5086 0.0909 0.0582 0.0125 0.5668 11 0.5315 - 13.50mm 0.6406 - 41/64"
3/4" 0.7500 0.6219 0.1000 0.0640 0.0137 0.6860 10 0.6406 - 41/64" 0.7656 - 49/64"
7/8" 0.8750 0.7327 0.1111 0.0711 0.0153 0.8039 9 0.7579 - 19.25mm 0.8906 - 57/64"
1" 1.0000 0.8399 0.1250 0.0800 0.0172 0.9200 8 0.8661 - 22.00mm 1.0156 - 1-1/64"
1-1/8" 1.1250 0.9420 0.1429 0.0915 0.0196 1.0335 7 0.9744 - 24.75mm 1.1405 - 1-9/64"
1-1/4" 1.2500 1.0670 0.1429 0.0915 0.0196 1.1585 7 1.0938 - 1-3/32" 1.2656 - 1-17/64"
1-1/2" 1.5000 1.2866 0.1667 0.1067 0.0229 1.3933 6 1.3189 - 33.50mm 1.5156 - 1-33/64"
1-3/4" 1.7500 1.4939 0.2000 0.1281 0.0275 1.6219 5 1.5354 - 39.00mm 1.8906 - 1-57/64"
2" 2.0000 1.7154 0.2222 0.1423 0.0305 1.8577 1.7520 - 44.50mm 2.0156 - 2-1/64"


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