ASME B18.2.2 Hex Flat Nuts

ASME B18.2.2 Hex Flat 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 Flat Nuts Dimensions (mm)

Nominal Size	Basic Major Diameter of Thread	Width Across Flats, F			Width Across Corners, G		Thickness, H			Runout, FIM
		Basic	Min.	Max.	Min.	Max.	Basic	Min.	Max.
1 1/8	28.575	42.863	41.427	42.875	47.219	49.505	25.400	24.638	26.162	0.737
1 1/4	31.750	47.625	46.025	47.625	52.476	54.991	27.781	26.975	28.600	0.813
1 3/8	34.925	52.388	50.648	52.375	57.734	60.503	30.559	29.693	31.420	0.889
1 1/2	38.100	57.150	55.245	57.150	62.992	65.989	33.338	32.410	34.239	0.991

ASME B18.2.2 Hex Flat Nuts Dimensions (Inch)

Nominal Size	Basic Major Diameter of Thread	Width Across Flats, F			Width Across Corners, G		Thickness, H			Runout, FIM
		Basic	Min.	Max.	Min.	Max.	Basic	Min.	Max.
1 1/8	1.1250	1 11/16	1.631	1.688	1.859	1.949	1	0.970	1.030	0.029
1 1/4	1.2500	1 7/8	1.812	1.875	2.066	2.165	1 3/32	1.062	1.126	0.032
1 3/8	1.3750	2 1/16	1.994	2.062	2.273	2.382	1 13/64	1.169	1.237	0.035
1 1/2	1.5000	2 1/4	2.175	2.250	2.480	2.598	1 5/16	1.276	1.348	0.039