螺纹尺寸表(3级普通螺纹)螺纹代号M 螺距t底孔直径d(I)底孔直径d(II)大端直径D 大端直径D®)鱒铁)GB70-86內八角螺钉GB65-86 圆柱头螺钉Ml0. 250. 750. 7Ml. 20. 250. 950.9Ml. 40. 31. 11.05Ml. 60. 351.251.2M20.41.61. 553. 5M2. 20. 451. 751. 7M2. 50. 452. 0524.2M30. 52. 52. 455M3. 50.62.9M40. 73. 33.277M4. 50. 75M50.84.24. 1& 5& 5M6154.91010M81.256. 756.612. 512. 5MIO1. 5& 58.31515M121. 7510. 25101818(Ml 4)2122121M1621413.82424大端直径DGB66-86沉头螺钉7. 5111518222529(M18)2.515.5M202.517.517.2(M22)2.519.5M2432120.7M303.526.526.1M3643231.5M424.540.537M4854342.4M52547M565.550.5M605.554.5M64658M6866227273230 3033364236螺纹尺寸表 （3级普通螺纹）。