美制外螺纹(2A)常用规格极限尺寸表(粗牙) ?公称尺寸和每英寸牙 螺纹系列 数 代号 ?8-32 (0.164-32) ?10-24 (0.190-24) ?12-24 (0.216-24) ?1/4-20 (0.250-20) ?5/16-18 (0.3175-18) ?3/8-16 (0.375-16) ?7/16-14 (0.4375-14) ?1/2-13 (0.50-13) 9/16-12 (0.5625-12) ?5/8-11 (0.625-11) ?3/4-10 (0.750-10) ?7/8-9 (0.875-9) 1"-8 (1.000-8) 大径极限 最小 0.1571 3.9903 0.1818 4.6177 0.2078 5.2781 0.2408 6.1163 0.3026 7.686 0.3643 9.2532 0.4258 10.8153 0.4876 12.385 0.5495 13.9573 0.6113 15.527 0.7353 18.6766 0.8592 21.8237 0.983 24.9682 最大 0.1631 4.1427 0.189 4.8006 0.215 5.461 0.2489 6.3221 0.3113 7.907 0.3737 9.492 0.4361 11.0769 0.4985 12.6619 0.5609 14.2469 0.6234 15.8344 0.7482 19.0043 0.8731 22.1767 0.998 25.3492 中径极限 最小 0.1399 3.5535 0.1586 4.0284 0.1845 4.6863 0.2127 5.4026 0.2712 6.8885 0.3287 8.349 0.385 9.779 0.4435 11.2649 0.5016 12.7406 0.5589 14.1961 0.6773 17.2034 0.7946 20.1828 0.91 23.114 最大 0.1428 3.6271 0.1619 4.1123 0.1879 4.7727 0.2164 5.4966 0.2752 6.9901 0.3331 8.4607 0.3897 9.8984 0.4485 11.3919 0.5068 12.8727 0.5644 14.3358