ASME B18.2.1 Askew head Bolts

                                                                                         

Nominal Size or Basic Product Diameter [Note (2)]	Body Diameter, E (See Para. 3.5)		Width Across Flats, F (See Para. 2.1.2)			Width Across Corners, G		Head Height, H [Note (3)]		Mid height, H [Note (3)]	Radius of Fillet, R		Maximum Unthreaded Length, S [Note (4)]	Thread Length for Bolt Lengths, LT [Note (4)]
														6 in. and Shorter	Over 6 in.
	Max.	Min.	Basic	Max.	Min.	Max.	Min.	Max.	Min.	Ref.	Max.	Min.		Nom.	Nom.
ASME B18.2.1 - 3⁄8	0.375	0.388	9⁄16	0.562	0.544	0.795	0.747	0.317	0.277	0.25	0.03	0.01	0.25	1	1.25
ASME B18.2.1 - 1⁄2	0.5	0.515	3⁄4	0.75	0.725	1.061	0.995	0.411	0.371	0.328	0.03	0.01	0.312	1.25	1.5
ASME B18.2.1 - 5⁄8	0.625	0.642	15⁄16	0.938	0.906	1.326	1.244	0.52	0.48	0.422	0.06	0.02	0.344	1.5	1.75
ASME B18.2.1 - 3⁄4	0.75	0.768	1 1⁄8	1.125	1.088	1.591	1.494	0.614	0.574	0.5	0.06	0.02	0.406	1.75	2
ASME B18.2.1 - 7⁄8	0.875	0.895	1 5⁄16	1.312	1.269	1.856	1.742	0.723	0.683	0.594	0.06	0.02	0.438	2	2.25
ASME B18.2.1 - 1	1	1.022	1 1⁄2	1.5	1.45	2.121	1.991	0.801	0.761	0.656	0.09	0.03	0.5	2.25	2.5
NOTES: (1) Bearing Surface. A die seam across the bearing surface is permissible. Angle of bearing surface with respect to shank is based on the 2 in. 12 slope of the inner flange of American Standard beams and channels. (2) Thread Series. Askew head bolts are only available with unified course (UNC) threads. (3) Head Height. Midheight, H, is a reference dimension and equals the basic head height of square bolts as given in Table 2. Head height, H1, is computed as midheight, H, + 0.0833 times the specified maximum width across flats, F. Tolerance on head height, H1, is ±0.020 in. from computed head height. (4) Thread Length. All askew head bolts of nominal lengths equal to or shorter than the nominal thread length, LT, plus the unthreaded length, S, shall be threaded for full length. The distance from the bearing surface of the head, as measured at midheight of head to the last scratch of thread, shall not exceed the unthreaded length, S. The distance from the bearing surface of the head, as measured at midheight, to the first complete (full form) thread, as measured with a nonchamfered GO thread ring gage assembled by hand as far as the thread will permit, shall not exceed the unthreaded length, S, plus a length of 2 1⁄2 threads