ASME B18.2.2 Large Hex Flange Nuts

ASME B18.2.2 Large Hex Flange 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 Large Hex Flange Nuts Dimensions (mm)

Nominal Size	Basic Major Diameter of Thread	Width Across Flats, F		Width Across Corners, G		Diameter Flange, B		Nut Thickness, H		Minimum Wrenching Length, J	Minimum Flange Thickness, K	Maximum Runout of Bearing Surface to Thread Axis, FIM (mm)
		Min.	Max.	Min.	Max.	Min.	Max.	Min.	Max.
ASME B18.2.2 - 1⁄4	6.350	10.871	11.125	12.395	12.827	17.780	18.491	7.137	7.925	3.810	1.016	0.610
ASME B18.2.2 - 5⁄16	7.938	12.421	12.700	14.148	14.656	20.066	20.828	8.712	9.525	5.080	1.016	0.711
ASME B18.2.2 - 3⁄8	9.525	13.995	14.275	15.951	16.510	22.479	23.241	9.906	10.312	6.096	1.016	0.787
ASME B18.2.2 - 7⁄16	11.113	17.145	17.475	19.507	20.168	27.940	28.727	11.100	11.887	6.604	1.016	0.965
ASME B18.2.2 - 1⁄2	12.700	18.694	19.050	21.336	21.996	29.845	30.607	12.319	13.081	7.366	1.524	1.041
ASME B18.2.2 - 9⁄16	14.288	21.869	22.225	24.943	25.654	32.004	33.020	13.868	14.681	9.398	1.524	1.118
ASME B18.2.2 - 5⁄8	15.875	23.419	23.825	26.695	27.508	32.512	34.544	15.240	16.256	10.668	1.524	1.143
GENERAL NOTES: (a) For additional requirements refer to section 3, General Data. (b) Concentricity of Tapped Hole. Axis of tapped hole shall be concentric with axis of nut body within a tolerance equal to 3% (6% FIM) of the maximum width across flats.

ASME B18.2.2 Large Hex Flange Nuts Dimensions (Inch)

Nominal Size	Basic Major Diameter of Thread	Width Across Flats, F		Width Across Corners, G		Diameter Flange, B		Nut Thickness, H		Minimum Wrenching Length, J	Minimum Flange Thickness, K	Maximum Runout of Bearing Surface to Thread Axis, FIM
		Min.	Max.	Min.	Max.	Min.	Max.	Min.	Max.
ASME B18.2.2 - 1⁄4	0.25	0.428	0.438	0.488	0.505	0.7	0.728	0.281	0.312	0.15	0.04	0.024
ASME B18.2.2 - 5⁄16	0.3125	0.489	0.5	0.557	0.577	0.79	0.82	0.343	0.375	0.2	0.04	0.028
ASME B18.2.2 - 3⁄8	0.375	0.551	0.562	0.628	0.65	0.885	0.915	0.39	0.406	0.24	0.04	0.031
ASME B18.2.2 - 7⁄16	0.4375	0.675	0.688	0.768	0.794	1.1	1.131	0.437	0.468	0.26	0.04	0.038
ASME B18.2.2 - 1⁄2	0.5	0.736	0.75	0.84	0.866	1.175	1.205	0.485	0.515	0.29	0.06	0.041
ASME B18.2.2 - 9⁄16	0.5625	0.861	0.875	0.982	1.01	1.26	1.3	0.546	0.578	0.37	0.06	0.044
ASME B18.2.2 - 5⁄8	0.625	0.922	0.938	1.051	1.083	1.28	1.36	0.6	0.64	0.42	0.06	0.045
GENERAL NOTES: (a) For additional requirements refer to section 3, General Data. (b) Concentricity of Tapped Hole. Axis of tapped hole shall be concentric with axis of nut body within a tolerance equal to 3% (6% FIM) of the maximum width across flats.