JIS B 1181 Hexagon Nuts

BS 1768

Table 3 — Unified hexagon slotted nuts and thick slotted nuts — Normal series

1	2	3	4	5	6	7	8	9	10	11	12	13	14
Nominal size D	Slotted nuts				Thick slotted nuts				Slotted nuts and thick slotted nuts			Maximum off-centre distance between centre line of slot and tapped hole	Tolerance on squareness of thread to face of nut
	Thickness G		Lower face of nut to bottom of slot H		Thickness J		Lower face of nut to bottom of slot K		Width of slot M		Depth of slot N		Tolerance on squareness of thread to face of nut
	Max.	Min.	Max.	Min.	Max.	Min.	Max.	Min.	Max.	Min.	Nom.		Max.
in	in	in	in	in	in	in	in	in	in	in	in	in	in
1/4	0.224	0.214	0.161	0.151	0.286	0.276	0.224	0.214	0.088	0.078	0.062	0.012	0.007
5/16	0.271	0.261	0.177	0.167	0.333	0.323	0.239	0.229	0.104	0.094	0.094	0.012	0.009
3/8	0.333	0.323	0.224	0.214	0.411	0.401	0.302	0.292	0.135	0.125	0.109	0.012	0.010
7/16	0.380	0.370	0.255	0.245	0.458	0.448	0.333	0.323	0.135	0.125	0.125	0.014	0.011
1/2	0.442	0.432	0.302	0.292	0.567	0.557	0.427	0.417	0.166	0.156	0.141	0.014	0.013
^a 9/16	0.489	0.479	0.333	0.323	0.614	0.604	0.458	0.448	0.166	0.156	0.156	0.017	0.013
5/8	0.552	0.542	0.364	0.354	0.724	0.714	0.536	0.526	0.198	0.188	0.187	0.017	0.014
3/4	0.651	0.631	0.432	0.412	0.822	0.802	0.604	0.584	0.198	0.188	0.219	0.022	0.017
7/8	0.760	0.740	0.510	0.490	0.916	0.896	0.666	0.646	0.198	0.188	0.250	0.022	0.020
1	0.874	0.844	0.593	0.563	1.015	0.985	0.734	0.704	0.260	0.250	0.281	0.027	0.020
1 1/8	0.989	0.949	0.661	0.621	1.176	1.136	0.848	0.808	0.260	0.250	0.328	0.027	0.024
1 1/4	1.087	1.037	0.728	0.678	1.275	1.225	0.916	0.866	0.322	0.312	0.359	0.032	0.024
^a 1 3/8	1.197	1.147	0.806	0.756	1.400	1.350	1.009	0.959	0.322	0.312	0.391	0.032	0.026
1 1/2	1.311	1.251	0.889	0.829	1.530	1.470	1.108	1.048	0.385	0.375	0.422	0.037	0.026
1 3/4	1.530	1.470	1.030	0.970	—	—	—	—	0.448	0.438	0.500	0.037	0.030
2	1.754	1.684	1.176	1.106	—	—	—	—	0.448	0.438	0.578	0.042	0.030
NOTE: In the case of the 7/16 in and 9/16 in nuts, the width across flats is 1/16 in larger than that of the corresponding bolt heads. This is in accordance with the American Standard from which these sizes are derived. ^a To be dispensed with wherever possible. For widths across flats, widths across corners, and diameter of washer face, see Table 2.