统一螺纹(UN)系列螺纹丝套规格、型式尺寸及安装参数表(3-1)
（No2-56UNC～7/16-32UN）
规格 公称直径(mm) 螺距(mm) 公称长度 钻孔深度 攻丝深度 钻孔直径(mm)
L1(mm) L2(mm) 切削丝锥 挤压丝锥
d p xd L(mm) min min min   max min   max
No2-56UNC 0.0860-56 2.184 0.45 1d 2.2 4.23 3.09 2.27 2.32 2.53 2.58
2.184 0.45 1.5d 3.3 5.32 4.18 2.27 2.32 2.53 2.58
2.184 0.45 2d 4.4 6.41 5.28 2.27 2.32 2.53 2.58
2.184 0.45 2.5d 5.5 7.50 6.37 2.27 2.32 2.53 2.58
2.184 0.45 3d 6.6 8.59 7.46 2.27 2.32 2.53 2.58
2.184 0.45 3.5d 7.6 9.69 8.55 2.27 2.32 2.53 2.58
2.184 0.45 4d 8.7 10.78 9.64 2.27 2.32 2.53 2.58
No2-64UNF 0.0860-64 2.184 0.40 1d 2.2 3.97 2.98 2.26 2.30 2.49 2.53
2.184 0.40 1.5d 3.3 5.06 4.07 2.26 2.30 2.49 2.53
2.184 0.40 2d 4.4 6.15 5.16 2.26 2.30 2.49 2.53
2.184 0.40 2.5d 5.5 7.25 6.25 2.26 2.30 2.49 2.53
2.184 0.40 3d 6.6 8.34 7.35 2.26 2.30 2.49 2.53
2.184 0.40 3.5d 7.6 9.43 8.44 2.26 2.30 2.49 2.53
2.184 0.40 4d 8.7 10.52 9.53 2.26 2.30 2.49 2.53
No3-48UNC 0.0990-48 2.515 0.53 1d 2.5 4.90 3.57 2.62 2.67 2.92 2.97
2.515 0.53 1.5d 3.8 6.15 4.83 2.62 2.67 2.92 2.97
2.515 0.53 2d 5.0 7.41 6.09 2.62 2.67 2.92 2.97
2.515 0.53 2.5d 6.3 8.67 7.34 2.62 2.67 2.92 2.97
2.515 0.53 3d 7.5 9.93 8.60 2.62 2.67 2.92 2.97
2.515 0.53 3.5d 8.8 11.18 9.86 2.62 2.67 2.92 2.97
2.515 0.53 4d 10.1 12.44 11.12 2.62 2.67 2.92 2.97
No3-56UNF 0.0990-56 2.515 0.45 1d 2.5 4.56 3.42 2.60 2.65 2.86 2.91
2.515 0.45 1.5d 3.8 5.81 4.68 2.60 2.65 2.86 2.91
2.515 0.45 2d 5.0 7.07 5.94 2.60 2.65 2.86 2.91
2.515 0.45 2.5d 6.3 8.33 7.19 2.60 2.65 2.86 2.91
2.515 0.45 3d 7.5 9.58 8.45 2.60 2.65 2.86 2.91
2.515 0.45 3.5d 8.8 10.84 9.71 2.60 2.65 2.86 2.91
2.515 0.45 4d 10.1 12.10 10.97 2.60 2.65 2.86 2.91
No4-40UNC 0.1120-40 2.845 0.64 1d 2.8 5.70 4.11 2.97 3.03 3.33 3.40
2.845 0.64 1.5d 4.3 7.12 5.54 2.97 3.03 3.33 3.40
2.845 0.64 2d 5.7 8.55 6.96 2.97 3.03 3.33 3.40
2.845 0.64 2.5d 7.1 9.97 8.38 2.97 3.03 3.33 3.40
2.845 0.64 3d 8.5 11.39 9.80 2.97 3.03 3.33 3.40
2.845 0.64 3.5d 10.0 12.81 11.23 2.97 3.03 3.33 3.40
2.845 0.64 4d 11.4 14.24 12.65 2.97 3.03 3.33 3.40
No4-48UNF 0.1120-48 2.845 0.53 1d 2.8 5.23 3.90 2.95 3.00 3.25 3.30
2.845 0.53 1.5d 4.3 6.65 5.33 2.95 3.00 3.25 3.30
2.845 0.53 2d 5.7 8.07 6.75 2.95 3.00 3.25 3.30
2.845 0.53 2.5d 7.1 9.49 8.17 2.95 3.00 3.25 3.30
2.845 0.53 3d 8.5 10.92 9.59 2.95 3.00 3.25 3.30
2.845 0.53 3.5d 10.0 12.34 11.02 2.95 3.00 3.25 3.30
2.845 0.53 4d 11.4 13.76 12.44 2.95 3.00 3.25 3.30
No5-40UNC 0.1250-40 3.175 0.64 1d 3.2 6.03 4.45 3.30 3.36 3.66 3.73
3.175 0.64 1.5d 4.8 7.62 6.03 3.30 3.36 3.66 3.73
3.175 0.64 2d 6.4 9.21 7.62 3.30 3.36 3.66 3.73
3.175 0.64 2.5d 7.9 10.80 9.21 3.30 3.36 3.66 3.73
3.175 0.64 3d 9.5 12.38 10.80 3.30 3.36 3.66 3.73
3.175 0.64 3.5d 11.1 13.97 12.38 3.30 3.36 3.66 3.73
3.175 0.64 4d 12.7 15.56 13.97 3.30 3.36 3.66 3.73
No5-44UNF 0.1250-44 3.175 0.58 1d 3.2 5.77 4.33 3.29 3.35 3.62 3.68
3.175 0.58 1.5d 4.8 7.36 5.92 3.29 3.35 3.62 3.68
3.175 0.58 2d 6.4 8.95 7.50 3.29 3.35 3.62 3.68
3.175 0.58 2.5d 7.9 10.54 9.09 3.29 3.35 3.62 3.68
3.175 0.58 3d 9.5 12.12 10.68 3.29 3.35 3.62 3.68
3.175 0.58 3.5d 11.1 13.71 12.27 3.29 3.35 3.62 3.68
3.175 0.58 4d 12.7 15.30 13.85 3.29 3.35 3.62 3.68
No6-32UNC 0.1380-32 3.505 0.79 1d 3.5 7.08 5.09 3.66 3.74 4.12 4.19
3.505 0.79 1.5d 5.3 8.83 6.85 3.66 3.74 4.12 4.19
3.505 0.79 2d 7.0 10.58 8.60 3.66 3.74 4.12 4.19
3.505 0.79 2.5d 8.8 12.33 10.35 3.66 3.74 4.12 4.19
3.505 0.79 3d 10.5 14.09 12.10 3.66 3.74 4.12 4.19
3.505 0.79 3.5d 12.3 15.84 13.86 3.66 3.74 4.12 4.19
3.505 0.79 4d 14.0 17.59 15.61 3.66 3.74 4.12 4.19
No6-40UNF 0.1380-40 3.505 0.64 1d 3.5 6.36 4.78 3.63 3.70 3.99 4.06
3.505 0.64 1.5d 5.3 8.12 6.53 3.63 3.70 3.99 4.06
3.505 0.64 2d 7.0 9.87 8.28 3.63 3.70 3.99 4.06
3.505 0.64 2.5d 8.8 11.62 10.03 3.63 3.70 3.99 4.06
3.505 0.64 3d 10.5 13.37 11.79 3.63 3.70 3.99 4.06
3.505 0.64 3.5d 12.3 15.13 13.54 3.63 3.70 3.99 4.06
3.505 0.64 4d 14.0 16.88 15.29 3.63 3.70 3.99 4.06
No8-32UNC 0.1640-32 4.166 0.79 1d 4.2 7.74 5.75 4.32 4.40 4.78 4.86
4.166 0.79 1.5d 6.2 9.82 7.84 4.32 4.40 4.78 4.86
4.166 0.79 2d 8.3 11.90 9.92 4.32 4.40 4.78 4.86
4.166 0.79 2.5d 10.4 13.99 12.00 4.32 4.40 4.78 4.86
4.166 0.79 3d 12.5 16.07 14.08 4.32 4.40 4.78 4.86
4.166 0.79 3.5d 14.6 18.15 16.17 4.32 4.40 4.78 4.86
4.166 0.79 4d 16.7 20.23 18.25 4.32 4.40 4.78 4.86
No8-36UNF 0.1640-36 4.166 0.71 1d 4.2 7.34 5.58 4.31 4.38 4.71 4.78
4.166 0.71 1.5d 6.2 9.42 7.66 4.31 4.38 4.71 4.78
4.166 0.71 2d 8.3 11.51 9.74 4.31 4.38 4.71 4.78
4.166 0.71 2.5d 10.4 13.59 11.83 4.31 4.38 4.71 4.78
4.166 0.71 3d 12.5 15.67 13.91 4.31 4.38 4.71 4.78
4.166 0.71 3.5d 14.6 17.75 15.99 4.31 4.38 4.71 4.78
4.166 0.71 4d 16.7 19.84 18.07 4.31 4.38 4.71 4.78
No10-24UNC 0.1900-24 4.826 1.06 1d 4.8 9.59 6.94 5.04 5.14 5.64 5.75
4.826 1.06 1.5d 7.2 12.00 9.36 5.04 5.14 5.64 5.75
4.826 1.06 2d 9.7 14.41 11.77 5.04 5.14 5.64 5.75
4.826 1.06 2.5d 12.1 16.83 14.18 5.04 5.14 5.64 5.75
4.826 1.06 3d 14.5 19.24 16.59 5.04 5.14 5.64 5.75
4.826 1.06 3.5d 16.9 21.65 19.01 5.04 5.14 5.64 5.75
4.826 1.06 4d 19.3 24.07 21.42 5.04 5.14 5.64 5.75
No10-32UNF 0.1900-32 4.826 0.79 1d 4.8 8.40 6.41 4.98 5.06 5.44 5.52
4.826 0.79 1.5d 7.2 10.81 8.83 4.98 5.06 5.44 5.52
4.826 0.79 2d 9.7 13.22 11.24 4.98 5.06 5.44 5.52
4.826 0.79 2.5d 12.1 15.64 13.65 4.98 5.06 5.44 5.52
4.826 0.79 3d 14.5 18.05 16.07 4.98 5.06 5.44 5.52
4.826 0.79 3.5d 16.9 20.46 18.48 4.98 5.06 5.44 5.52
4.826 0.79 4d 19.3 22.88 20.89 4.98 5.06 5.44 5.52
No12-24UNC 0.2160-24 5.486 1.06 1d 5.5 10.25 7.60 5.70 5.80 6.30 6.41
5.486 1.06 1.5d 8.2 12.99 10.35 5.70 5.80 6.30 6.41
5.486 1.06 2d 11.0 15.74 13.09 5.70 5.80 6.30 6.41
5.486 1.06 2.5d 13.7 18.48 15.83 5.70 5.80 6.30 6.41
5.486 1.06 3d 16.5 21.22 18.58 5.70 5.80 6.30 6.41
5.486 1.06 3.5d 19.2 23.96 21.32 5.70 5.80 6.30 6.41
5.486 1.06 4d 21.9 26.71 24.06 5.70 5.80 6.30 6.41
No12-28UNF 0.2160-28 5.486 0.91 1d 5.5 9.57 7.30 5.67 5.76 6.18 6.27
5.486 0.91 1.5d 8.2 12.31 10.04 5.67 5.76 6.18 6.27
5.486 0.91 2d 11.0 15.05 12.79 5.67 5.76 6.18 6.27
5.486 0.91 2.5d 13.7 17.80 15.53 5.67 5.76 6.18 6.27
5.486 0.91 3d 16.5 20.54 18.27 5.67 5.76 6.18 6.27
5.486 0.91 3.5d 19.2 23.28 21.02 5.67 5.76 6.18 6.27
5.486 0.91 4d 21.9 26.03 23.76 5.67 5.76 6.18 6.27
No12-32UNEF 0.2160-32 5.486 0.79 1d 5.5 9.06 7.07 5.64 5.72 6.10 6.18
5.486 0.79 1.5d 8.2 11.80 9.82 5.64 5.72 6.10 6.18
5.486 0.79 2d 11.0 14.54 12.56 5.64 5.72 6.10 6.18
5.486 0.79 2.5d 13.7 17.29 15.30 5.64 5.72 6.10 6.18
5.486 0.79 3d 16.5 20.03 18.05 5.64 5.72 6.10 6.18
5.486 0.79 3.5d 19.2 22.77 20.79 5.64 5.72 6.10 6.18
5.486 0.79 4d 21.9 25.52 23.53 5.64 5.72 6.10 6.18
1/4-20UNC 0.2500-20 6.350 1.27 1d 6.4 12.07 8.89 6.60 6.73 7.33 7.45
6.350 1.27 1.5d 9.5 15.24 12.07