BS 916 Hexagon Lock Nut

Hexagon Lock Nuts

BS 916 Hexagon Lock Nut

Nominal size
D
Number of threads
per inch
Width across flats
A
Approx. max.
width across corners
C
Thickness of nut
E
Thickness of nut
F
Tolerance for squareness of thread to face of nut
(see Clause 10)
Faced one side Faced
both side
Black Faced
both side
Black Machined
B.S.W B.S.F max. min. Hexagon. square. min. max. min. max. min. max. min. max. max.
in. in. in. in. in. in. in. in. in. in. in. in. in. in.
¼ 20 26 0.445 0.435 0.51 0.63 0.180 0.200 0.190 0.185 0.180 -- -- 0.014 0.007
⁵⁄₁₆ 18 22 0.525 0.515 0.61 0.74 0.230 0.250 0.240 0.210 0.200 -- -- 0.018 0.009
16 20 0.600 0.585 0.69 0.85 0.292 0.312 0.302 0.260 0.250 -- -- 0.020 0.010
⁷⁄₁₆ 14 18 0.710 0.695 0.82 1.00 0.355 0.375 0.365 0.275 0.265 -- -- 0.022 0.011
½ 12 16 0.820 0.800 0.95 1.16 0.417 0.437 0.427 0.300 0.290 -- -- 0.026 0.013
⁹⁄₁₆ 12 16 0.920 0.900 1.06 1.30 0.480 0.500 0.490 0.333 0.323 -- -- 0.026 0.013
11 14 1.010 0.985 1.17 1.43 0.542 0.562 0.552 0.410 0.375 0.375 0.365 0.028 0.014
¾ 10 12 1.200 1.175 1.39 1.70 0.668 0.687 0.677 0.490 0.458 0.448 0.448 0.034 0.017
9 11 1.300 1.270 1.50 1.84 0.720 0.750 0.740 0.550 0.500 0.500 0.490 0.040 0.020
1 8 10 1.480 1.450 1.71 2.09 0.835 0.875 0.865 0.630 0.583 0.583 0.573 0.040 0.020
1⅛ 7 9 1.670 1.640 1.93 2.36 0.960 1.000 0.990 0.720 0.666 0.666 0.656 0.048 0.024
7 9 1.860 1.815 215 2.63 1.080 1.125 1.105 0.810 0.750 0.750 0.730 0.048 0.024
1⅜a 6 8 2.050 2.005 2.37 2.90 1.190 1.250 1.230 0.890 0.833 0.833 0.813 0.052 0.026
6 8 2.220 2.175 2.56 3.14 1.315 1.375 1.355 0.980 0.916 0.916 0.896 0.052 0.026
1⅝a 5 8 2.410 2.365 2.78 3.41 1.440 1.500 1.480 1.060 1.000 1.000 0.980 0.052 0.026
5 7 2.580 2.520 2.98 3.65 1.565 1.625 1.605 1.160 1.083 1.083 1.063 1.060 1.030
2 4.5 7 2.760 2.700 3.19 3.90 1.690 1.750 1.730 1.250 1.166 1.166 1.146 0.060 0.030
4 6 3.150 3.090 3.64 4.45 1.815 1.875 1.855 1.430 1.250 1.250 1.229 0.060 0.030
4 6 3.550 3.490 4.10 5.02 2.065 2.125 2.105 1.600 1.416 1.416 1.396 0.070 0.035
3.5 6 3.830 3.830 4.49 5.50 2.315 2.375 2.355 1.770 1.580 1.580 1.560 0.070 0.035
3 3.5 5 4.180 4.080 4.83 5.91 2.525 2.625 2.605 1.980 1.750 1.750 1.730 0.080 0.040
a 3.25 5 4.530 4.430 5.23 6.41 2.775 2.875 2.845 2.150 1.915 1.915 1.882 0.080 0.040
3.25 4.5 4.850 4.750 5.60 6.86 3.025 3.125 3.095 2.320 2.083 2.083 2.051 2.090 2.045
a 3 4.5 5.180 5.080 5.98 7.33 3.275 3.375 3.345 2.480 2.250 2.250 2.212 0.090 0.045
4 3 4.5 5.550 5.450 6.41 7.85 3.525 3.625 3.595 2.650 2.417 2.417 2.387 0.100 0.050
2.875 4 6.380 6.255 7.37 9.02 3.850 4.000 3.970 3.030 2.666 2.666 2.636 0.110 0.055
5 2.750 4 7.300 7.175 8.43 10.32 4.350 4.500 4.470 3.370 3.000 3.000 2.970 0.120 0.060
2.625 4 8.350 8.225 9.64 11.81 4.850 5.000 4.970 3.700 3.333 3.333 3.303 0.130 0.065
6 2.500 4 9.450 9.325 10.91 13.36 5.350 5.500 5.470 4.030 3.666 3.666 3.636 0.140 0.070
a To be dispensed with wherever possible.
The dimensions of black lock nuts in the above table are designed to permit the product to be manufactured by either hot forging.
cold forming or cold pressing, at the option of the manufacturer.