公制与英制对照表 八分英制 十分英制 公制(mm) 1/64 .016 0.397 1/32 .031 0.794 3/64 .047 1.191 1/16(半分) .063 1.588 5/64 .078 1.984 3/32 .094 2.381 7/64 .109 2.778 1/8(一分) .125 3.175 9/64 .141 3.572 5/32 .156 3.969 11/64 .172 4.366 3/16(一分半) .188 4.763 13/64 .203 5.159 7/32 .219 5.556 15/64 .234 5.953 1/4(二分) .250 6.35 17/64 .266 6.747 9/32 .218 7.144 19/64 .297 7.541 5/16(二分半) .313 7.938 21/64 .328 8.334 11/32 .344 8.731 23/64 .359 9.128 3/8(三分) .375 9.525 25/64 .391 9.922 13/32 .406 10.319 27/64 .422 10.716 7/16(三分半) .438 11.113 29/64 .453 11.509 15/32 .469 11.906 31/64 .484 12.303 1/2(四分) .500 12.7 八分英制 十分英制 公制(mm) 33/64 .516 13.097 17/32 .531 13.494 35/64 .547 13.891 9/16(四分半) .563 14.288 37/64 .578 14.684 19/32 .594 15.081 39/64 .609 15.478 5/8(五分) .625 15.875 41/64 .641 16.272 21/32 .656 16.669 43/64 .672 17.066 11/16(五分半) .688 17.463 45/64 .703 17.859 23/32 .719 18.256 47/64 .734 18.653 3/4(六分) .750 19.05 49/64 .766 19.447 25/32 .781 19.843 51/64 .797 20.241 13/16(六分半) .813 20.638 53/64 .828 21.034 27/32 .844 21.431 55/64 .859 21.828 7/8(七分) .875 22.225 57/64 .891 22.622 29/32 .906 23.019 59/64 .922 23.416 15/16(七分半) .938 23.813 61/64 .953 24.209 31/32 .969 24.606 63/64 .984 25.003 1(一寸) 1.000 25.4 八分英制 十分英制 公制(mm) 1 1.000 25.4 114 1.250 31.75 112 1.500 38.1 134 1.750 44.45 2 2.000 50.8 214 2.250 57.15 212 2.500 63.5 234 2.750 69.85 3 3.000 76.2 314 3.250 82.55 312 3.500 88.9 334 3.750 95.25 4 4.000 101.6 414 4.250 107.95 412 4.500 114.3 434 4.750 120.65 5 5.000 127 514 5.250 133.35 512 5.500 139.7 534 5.750 146.05 6 6.000 152.4 614 6.250 158.75 612 6.500 165.1 634 6.750 171.45 7 7.000 177.8 712 7.500 190.5 734 7.750 196.85 8 8.000 203.2 812 8.500 215.9 834 8.750 222.25 9 9.000 228.6 10 10.000 254 本文来源：https://www.wddqw.com/doc/772b1b1ca300a6c30c229f46.html