ASME B18.2.2 Hex Nuts

ASME B18.2.2 Hex Nuts Standard covers the dimensional requirements for nine product types of inch series bolts and screws recognized as American National Standard. Also included are appendices covering gaging procedures, grade markings for bolts and screws, formulas on which dimensional data are based, and a specification to assist in identifying a product as being a screw or a bolt. Where questions arise concerning acceptance of product, the dimensions in the tables shall govern over recalculation by formula. Heavy hex structural bolts, formerly covered in ASME B18.2.1, are now covered in ASME B18.2.6.
The inclusion of dimensional data in this Standard is not intended to imply that all of the products described herein are stock production sizes. Consumers should consult with suppliers concerning lists of stock production sizes.

ASME B18.2.2 Hex Nuts Dimensions (mm)

Nominal Size	Basic Major Diameter of Thread	Width Across Flats, F		Width Across Corners, G		Thickness, H		Maximum Runout of Bearing Surface to Thread Axis, FIM
		Min.	Max	Min.	Max	Min.	Max	Up to 150,000 psi	150,000 psi and Greater
1/4	6.35	10.8712	11.1252	12.3952	12.827	5.3848	5.7404	0.381	0.254
5/16	7.9375	12.4206	12.7	14.1478	14.6558	6.5532	6.9342	0.4064	0.2794
3/8	9.525	13.9954	14.3002	15.9512	16.51	8.128	8.5598	0.4318	0.3048
7/16	11.1125	17.145	17.4752	19.5072	20.1676	9.271	9.779	0.4572	0.3302
1/2	12.7	18.6944	19.05	21.336	21.9964	10.8458	11.3792	0.4826	0.3556
9/16	14.2875	21.8694	22.225	24.9428	25.654	12.0142	12.5984	0.508	0.381
5/8	15.875	23.4188	23.8252	26.6954	27.5082	13.589	14.1986	0.5334	0.4064
3/4	19.05	27.6352	28.575	31.496	32.9946	15.6718	16.891	0.5842	0.4572
7/8	22.225	32.2326	33.3248	36.7538	38.5064	18.3896	19.7104	0.635	0.508
1	25.4	36.83	38.1	41.9862	43.9928	21.1074	22.5298	0.6858	0.5588
1 1/8	28.575	41.4274	42.8752	47.2186	49.5046	23.8506	25.3746	0.762	0.635
1 1/4	31.75	46.0248	47.625	52.4764	54.991	26.162	27.7876	0.8382	0.7112
1 3/8	34.925	50.6476	52.3748	57.7342	60.5028	28.9052	30.6324	0.9144	0.7874
1 1/2	38.1	55.245	57.15	62.992	65.9892	31.623	33.4518	0.9906	0.8636
1 5/8	41.275	59.69	61.722	68.0466	71.247	34.6456	35.9664	1.1176	0.9652
1 3/4	44.45	64.4652	66.675	73.4822	76.9874	37.084	39.116	1.2192	1.0414
1 7/8	47.625	69.1388	71.4502	78.8162	82.4738	39.8018	41.9354	1.2954	1.1176
2	50.8	73.66	76.2	83.9724	87.9856	42.545	44.7802	1.397	1.1938
2 1/4	57.15	82.8802	85.725	94.4626	98.9838	48.006	50.4444	1.5494	1.3208
2 1/2	63.5	92.075	95.25	104.9782	109.982	53.467	56.1086	1.7272	1.4732
2 3/4	69.85	101.2952	104.775	115.4684	120.9802	58.9026	61.7474	1.8796	1.6256
3	76.2	110.49	114.3	125.9586	131.9784	64.3636	67.4116	2.0574	1.778
3 1/4	82.55	119.7102	123.825	136.4742	142.9766	69.8246	73.0758	2.2098	1.905
3 1/2	88.9	128.905	133.35	146.9644	153.9748	75.2856	78.74	2.3876	2.0574
3 3/4	95.25	138.1252	142.875	157.4546	164.973	80.7212	84.3788	2.54	2.2098
4	101.6	147.32	152.4	167.9448	175.9712	86.1822	90.043	2.7178	2.3622

ASME B18.2.2 Hex Nuts Dimensions (Inch)

Nominal Size	Basic Major Diameter of Thread	Width Across Flats, F		Width Across Corners, G		Thickness, H		Maximum Runout of Bearing Surface to Thread Axis, FIM
		Min.	Max	Min.	Max	Min.	Max	Up to 150,000 psi	150,000 psi and Greater
1/4	0.2500	0.428	0.438	0.488	0.505	0.212	0.226	0.015	0.010
5/16	0.3125	0.489	0.500	0.557	0.577	0.258	0.273	0.016	0.011
3/8	0.3750	0.551	0.563	0.628	0.650	0.320	0.337	0.017	0.012
7/16	0.4375	0.675	0.688	0.768	0.794	0.365	0.385	0.018	0.013
1/2	0.5000	0.736	0.750	0.840	0.866	0.427	0.448	0.019	0.014
9/16	0.5625	0.861	0.875	0.982	1.010	0.473	0.496	0.020	0.015
5/8	0.6250	0.922	0.938	1.051	1.083	0.535	0.559	0.021	0.016
3/4	0.7500	1.088	1.125	1.240	1.299	0.617	0.665	0.023	0.018
7/8	0.8750	1.269	1.312	1.447	1.516	0.724	0.776	0.025	0.020
1	1.0000	1.450	1.500	1.653	1.732	0.831	0.887	0.027	0.022
1 1/8	1.1250	1.631	1.688	1.859	1.949	0.939	0.999	0.030	0.025
1 1/4	1.2500	1.812	1.875	2.066	2.165	1.030	1.094	0.033	0.028
1 3/8	1.3750	1.994	2.062	2.273	2.382	1.138	1.206	0.036	0.031
1 1/2	1.5000	2.175	2.250	2.480	2.598	1.245	1.317	0.039	0.034
1 5/8	1.6250	2.35	2.43	2.679	2.805	1.364	1.416	0.044	0.038
1 3/4	1.7500	2.538	2.625	2.893	3.031	1.460	1.540	0.048	0.041
1 7/8	1.8750	2.722	2.813	3.103	3.247	1.567	1.651	0.051	0.044
2	2.0000	2.900	3.000	3.306	3.464	1.675	1.763	0.055	0.047
2 1/4	2.2500	3.263	3.375	3.719	3.897	1.890	1.986	0.061	0.052
2 1/2	2.5000	3.625	3.750	4.133	4.330	2.105	2.209	0.068	0.058
2 3/4	2.7500	3.988	4.125	4.546	4.763	2.319	2.431	0.074	0.064
3	3.0000	4.350	4.500	4.959	5.196	2.534	2.654	0.081	0.070
3 1/4	3.2500	4.713	4.875	5.373	5.629	2.749	2.877	0.087	0.075
3 1/2	3.5000	5.075	5.250	5.786	6.062	2.964	3.100	0.094	0.081
3 3/4	3.7500	5.438	5.625	6.199	6.495	3.178	3.322	0.100	0.087
4	4.0000	5.800	6.000	6.612	6.928	3.393	3.545	0.107	0.093