Pitch Diameter Tables – American Na tional Thread Form FOR NOS. 575 AND 585 SCREW THREAD MICROMETERS Number Sizes Caliper Reading or Pitch Diameter = D - .6495 N Fractional Sizes Caliper Reading or Pitch Diameter = D - .6495 N No. Basic and Max. Outside Diameter Threads Per Inch Caliper Reading or Max. Pitch Diameter Single Depth of Thread D N D - .6495 .6495 N N 0 .060 80 .0519 .0081 1 .073 72 .0640 .0090 2 .086 64 .0759 .0101 3 .099 56 .0874 .0116 4 .112 48 .0985 .0135 5 .125 44 .1102 .0148 6 .138 40 .1218 .0162 7 .151 36 .1330 .0180 8 .164 36 .1460 .0180 9 .177 32 .1567 .0203 10 .190 30 .1684 .0217 12 .216 28 .1928 .0232 14 .242 24 .2149 .0271 16 .268 22 .2385 .0295 18 .294 20 .2615 .0325 20 .320 20 .2875 .0325 22 .346 18 .3099 .0361 24 .372 16 .3314 .0406 26 .398 16 .3574 .0406 28 .424 14 .3776 .0464 30 .450 14 .4036 .0464 Diameter (in) Threads Per Inch Caliper Reading of Pitch Diameter Single Depth of Thread D N D - .6495 .6495 N N Note: As there is no standard of diameter for the finer pitches, this column is left blank. 64 — .0101 62 — .0105 60 — .0108 58 — .0112 56 — .0116 54 — .0120 52 — .0125 50 — .0130 48 — .0135 46 — .0141 44 — .0148 42 — .0155 40 — .0162 38 — .0171 36 — .0180 34 — .0191 32 — .0203 30 — .0217 28 — .0232 26 — .0250 24 — .0271 22 — .0295 1/4 20 .2175 .0325 5/16 18 .2764 .0361 3/8 16 .3344 .0406 7/16 14 .3911 .0464 1/2 13 .4501 .0499 9/16 12 .5084 .0541 5/8 11 .5660 .0590 3/4 10 .6851 .0649 7/8 9 .8029 .0721 1 8 .9188 .0812 1-1/8 7 1.0322 .0928 1-1/4 7 1.1572 .0928 1-3/8 6 1.2668 .1082 1-1/2 6 1.3918 .1082 1-5/8 5-1/2 1.5070 .1180 1-3/4 5 1.6201 .1299 1-7/8 5 1.7451 .1299 2 4-1/2 1.8557 .1443 2-1/2 4 2.3376 .1624 3 3-1/2 2.8145 .1855 3-1/2 3-1/4 3.3002 .1998 4 3 3.7835 .2165 586 R eference T ables