ASME B18.2.2 Heavy Square Nut Dimensions

Nominal Size	Basic Major Diameter of Thread	Width Across Flats, F			Width Across Corners, G		Thickness			Bearing Surface Runout to Thread Axis, FLM
		Basic	Min.	Max.	Min.	Max.	Basic	Min.	Max.
1/4	0.2500	1/2	0.488	0.500	0.640	0.707	1/4	0.218	0.266	0.026
5/16	0.3125	9/16	0.546	0.562	0.720	0.795	5/16	0.280	0.330	0.030
3/8	0.3750	11/16	0.688	0.699	0.889	0.973	3/8	0.341	0.393	0.038
7/16	0.4375	3/4	0.728	0.750	0.970	1.060	7/16	0.403	0.456	0.039
1/2	0.5000	7/8	0.850	0.875	1.137	1.237	1/2	0.464	0.520	0.046
5/8	0.6250	1 1/16	1.031	1.062	1.386	1.503	5/8	0.587	0.647	0.056
3/4	0.7500	1 1/4	1.212	1.25	1.635	1.768	3/4	0.710	0.774	0.065
7/8	0.8750	1 7/16	1.394	1.438	1.884	2.033	7/8	0.833	0.901	0.075
1	1.0000	1 5/8	1.575	1.625	2.132	2.298	1	0.956	1.028	0.082
1 1/8	1.1250	1 13/16	1.756	1.812	2.381	2.563	1 1/8	1.079	1.155	0.063
1 1/4	1.2500	2	1.938	2.000	2.631	2.828	1 1/4	1.187	1.282	0.070
1 3/8	1.3750	2 3/16	2.119	2.188	2.879	3.094	1 3/8	1.310	1.409	0.076
1 1/2	1.5000	2 3/8	2.300	2.375	3.128	3.359	1 1/2	1.433	1.536	0.082