3.12普通螺纹内、外螺纹余留长度、钻孔余留深度、螺栓突出螺母末端长度标准（JB/ZQ 4247—1997)
普通螺纹内、外螺纹余留长度、钻孔余留深度、螺栓突出螺母末端长度标准JB4247—1997
普通螺纹内、外螺纹余留长度、钻孔余留深度、螺栓突出螺母末端长度见表1.1-31。
表1.1-31普通螺纹内、外螺纹余留长度、钻孔余留深度、螺栓突出螺母末端长度（mm）
| 螺距 | 螺纹直径 | 余留长度 | 末端长度 | |||
| 粗牙 | 细牙 | 内螺纹 | 钻孔 | 外螺纹 | ||
| P | d | l1 | l2 | l3 | a | |
| 0.5 | 3 | 5 | 1 | 4 | 2 | 1〜2 |
| 0.7 | 4 | 5 | 2.5 | 2~3 | ||
| 0.75 | 6 | 1.5 | 6 | |||
| 0.8 | 5 | |||||
| 1 | 6 | 8, 10, 14, 16, 18 | 2 | 7 | 3.5 | 2.5-4 |
| 1.25 | 8 | 12 | 2.5 | 9 | 4 | |
| 1.5 | 10 | 14, 16, 18, 20, 22, 24, 27, 30, 33 | 3 | 10 | 4.5 | 3.5-5 |
| 1.75 | 12 | 3.5 | 13 | 5.5 | ||
| 2 | 14，16 | 24, 27, 30, 33， 36， 39, 45, 48, 52 | 4 | 14 | 6 | 4.5 〜6.5 |
| 2.5 | 18, 20, 22 | 5 | 17 | 7 | ||
| 3 | 24, 27 | 36, 39, 42, 45, 48, 56, 60, 64, 72, 76 | 6 | 20 | 8 | 5.5 〜8 |
| 3.5 | 30 | 7 | 23 | 10 | ||
| 4 | 36 | 56, 60, 64, 68, 72, 76 | 8 | 26 | 11 | 7〜11 |
| 4.5 | 42 | 9 | 30 | 12 | ||
| 5 | 48 | 10 | 33 | 13 | 10〜15 | |
| 5.5 | 56 | 11 | 36 | 16 | ||
| 6 | 64, 72, 76 | 12 | 40 | 18 | ||