Threads and Points For Type 1 Thread Cutting Screws ANSI/ASME B18.6.4 1981 Nominal Size Threads Per Inch Major Dia.(D) Point Dia.(P) Point Taper Length(S) Determinant Length For Point Taper(L) Minimum
Practical Nominal Screw Lengths(L) Short Screws Long Screws 90° Heads Csk Heads 90° Heads Csk Heads 2 56 .0860 .0813 .068 .062 .045 .080 .062 5/32 3/16 5/32 3/16 4 40 .1120 .1061 .087 .088 .062 .112 .088 7/32 1/4 3/16 1/4 6 32 .1380 .1312 .107 .109 .078 .141 .109 1/4 5/16 1/4 5/16 8 32 .1640 .1571 .132 .109 .078 .141 .109 1/4 11/32 1/4 5/16 10 24 .1900 .1818 .148 .146 .104 .188 .146 11/32 7/16 5/16 13/32 10 32 .1900 .1831 .158 .109 .078 .141 .109 1/4 11/32 1/4 5/16 12 24 .2160 .2078 .174 .146 .104 .188 .146 11/32 7/16 5/16 13/32 1/4 20 .2500 .2408 .200 .175 .125 .225 .175 13/32 17/32 3/8 1/2 5/16 18 .3125 .3026 .257 .194 .139 .250 .194 15/32 19/32 7/16 9/16 3/8 16 .3750 .3643 .312 .219 .156 .281 .219 1/2 11/16 15/32 5/8
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Test Plate Thickness & Hole Sizes for Types 1, 23 & F Nominal Size Thickness Hole Size 2-56 18 .0800 .0760 49 .0730 4-40 18 .1110 .1070 41 .0960 5-40 18 .1110 .1070 37 .1010 6-32 14 .1425 .1385 31 .1200 8-32 14 .1905 .1845 26 .1470 10-24 1/8 .1905 .1845 17 .1730 10-32 1/8 .1905 .1845 16 .1770 12-24 1/8 .1905 .1845 8 .1990 ¼-20 3/16 .2530 .2470 1 .2280 5/16-18 3/16 .3155 .3095 L .2900 3/8-16 3/16 .3780 .3720 T .3580 ½-13 3/16 .4710 .4430 29/64 .4531
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Hole Dia.
