Hexagon ordinary nuts and lock-nuts

1	2	3	4	5	6	7	8	9	10	11
nominal size D	Width across flats A		Width across corners C	Diameter of washer face E		Thickness				Tolerance on sqaurencess of thread to face of nut. See Clause 9
nominal size D	Width across flats A		Width across corners C	Diameter of washer face E		Ordinary nuts E		Lock-nuts F
	Max.	Min.	Max.	Max.	Min.	Max.	Min.	Max.	Min.	Max.
in	in	in	in	in	in	in	in	in	in	in
¼	0.445	0.438	0.51	0.428	0.418	0.200	0.190	0.133(0.161)	0.123(0.151)	0.007
⁵⁄₁₆	0.525	0.518	0.61	0.508	0.498	0.250	0.240	0.166(0.192)	0.156(0.182)	0.009
⅜	0.600	0.592	0.69	0.582	0.572	0.312	0.302	0.208(0.224)	0.198(0.214)	0.010
⁷⁄₁₆	0.710	0.702	0.82	0.690	0.680	0.375	0.365	0.250	0.240	0.011
½	0.820	0.812	0.95	0.800	0.790	0.437	0.427	0.291	0.281	0.013
⁹⁄₁₆	0.920	0.912	1.06	0.900	0.890	0.500	0.490	0.333	0.323	0.013
⅝	1.010	1.000	1.17	0.985	0.975	0.562	0.552	0.375	0.0365	0.014
¾	1.200	1.190	1.39	1.175	1.165	0.687	0.677	0.458	0.448	0.017
⅞	1.300	1.288	1.50	1.273	1.263	0.750	0.740	0.500	0.490	0.020
1	1.480	1.468	1.71	1.453	1.443	0.875	0.865	0.583	0.573	0.020
1⅛	1-670	1-640	1-93	1-620	1-610	1.000	0.990	0.66	0.656	0.024
1¼	1.860	1.815	2.15	1.795	1.785	1.125	1.105	0.750	0.730	0.024
1⅜	2.050	2.005	2.37	1.985	1.975	1.250	1.230	0.833	0.813	0.026
1½	2.220	2.175	2.56	2.155	2.145	1.375	1.355	0.916	0.896	0.026
1¾	2.580	2.520	2.98	2.495	2.485	1.625	1.605	1.083	1.063	0.030
2	2.760	2.700	3.19	2.675	2.665	1.750	1.730	1.166	1.146	0.030
Note standard with B.S.W. thread. When bolts from ¼ in to 1 in nominal size are hot forged, the tolerance on the width across flats shall be two and a half times the tolerance shown in the table and shall be unilaterally minus from maximumn size. Alternative thickness values have been provided, in parentheses, for size ¼ in, ⅜ in to cater for different manufacturing processes. This option shall not apply unless the purchaser in his enquiry and order specifically states which of the alternative thickness values he requires.