Lister 5/1 Diesel

Threading Tables

Chart No 8 - Model Engineer's and Admiralty Fine Threads


Model Engineer's Standard Threads (Whitworth Form)
Dimensions in Inches except where stated

Thread Form Data
Diameter O/Diameter Core Radius Depth Pitch Effective Dia T.P.I Tapping Drill
1/8" 0.125 0.0930 -- 0.0160 0.0250 0.1090 40 No 40
5/32" 0.1563 0.1242 -- 0.0160 0.0250 0.1403 40 No 30
3/16" 0.1875 0.1555 -- 0.0160 0.0250 0.1715 40 5/32"
7/32" 0.2188 0.1867 -- 0.0160 0.0250 0.2028 40 3/16"
1/4" 0.2500 0.2187 -- 0.0160 0.0250 0.2340 40 7/32"
9/32" 0.2813 0.2412 -- 0.0200 0.03125 0.2613 32 Letter C
5/16" 0.3125 0.2725 -- 0.0200 0.03125 0.2925 32 Letter J
3/8" 0.375 0.3350 -- 0.0200 0.03125 0.3550 32 Letter R
7/16" 0.4375 0.3833 -- 0.0246 0.03846 0.4129 26 10mm
1/2" 0.5000 0.4508 -- 0.0246 0.03846 0.4754 26 29/64"

Admiralty Fine Threads (Whitworth Form)
Dimensions in Inches except where stated

Thread Form Data
Component
Diameter
O/Diameter Core Radius Depth Pitch Effective Dia T.P.I Tapping Drill
Under 1/2" N/A N/A N/A 0.0267 0.04166 N/A 24 N/A
1/2" & under 3/4" N/A N/A N/A 0.0320 0.05000 N/A 20 N/A
3/4" & under 1" N/A N/A N/A 0.0457 0.07143 N/A 14 N/A
1" & under 2" N/A N/A N/A 0.0533 0.08333 N/A 12 N/A
2" & under 4" N/A N/A N/A 0.0800 0.12500 N/A 8 N/A
4" & over N/A N/A N/A 0.1067 0.16666 N/A 6 N/A

Used on pressure gauges and screwed glands on engines etc.


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