BS1083 Castle Nuts


Across Flat Overall
Thickness
Unslotted
Thickness
Slot
Width
Washer
Diameter

s m w n b

max min max min max min max min max min
1/4 0.445 0.438 0.290 0.280 0.200 0.190 0.100 0.090 0.428 0.418
5/16 0.525 0.518 0.340 0.330 0.250 0.240 0.100 0.090 0.508 0.498
3/8 0.600 0.592 0.402 0.392 0.312 0.302 0.100 0.090 0.582 0.572
7/16 0.710 0.702 0.515 0.505 0.375 0.365 0.135 0.125 0.690 0.680
1/2 0.820 0.812 0.577 0.567 0.437 0.427 0.135 0.125 0.800 0.790
9/16 0.920 0.912 0.687 0.677 0.500 0.490 0.175 0.165 0.900 0.890
5/8 1.010 1.000 0.749 0.739 0.562 0.552 0.175 0.165 0.985 0.975
3/4 1.200 1.190 0.921 0.911 0.687 0.677 0.218 0.208 1.175 1.165
7/8 1.300 1.288 0.984 0.974 0.750 0.740 0.218 0.208 1.273 1.263
1 1.480 1.468 1.155 1.145 0.875 0.865 0.260 0.250 1.453 1.443
1.1/8 1.670 1.640 1.280 1.270 1.000 0.990 0.260 0.250 1.620 1.610
1.1/4 1.860 1.815 1.453 1.433 1.125 1.105 0.300 0.290 1.795 1.785
1.3/8 2.050 2.005 1.578 1.558 1.250 1.230 0.300 0.290 1.985 1.975
1.1/2 2.220 2.175 1.703 1.683 1.375 1.355 0.300 0.290 2.155 2.145
1.3/4 2.580 2.520 2.000 1.980 1.625 1.605 0.343 0.333 2.495 2.485
2 2.760 2.700 2.218 2.198 1.750 1.730 0.426 0.416 2.675 2.665

It is at our discretion if the bottom of the slots are rounded or flat.

Washer faced nuts typical washer thickness = 0.015"