Stud and Nut Sizes

From our tables on Flange PCDs you can easily determine the recommended stud bolt diameter, and from the table below, you can determine the corresponding nut size. This allows the construction engineer to ensure all necessary hand tools of the correct size e.g. flogging spanners, ring spanners, socket sizes etc. are made available during construction.

Remember that if you plan to hydrotight the assembly, the studs will have to be longer than if tightened by hand.

AF - Across the Flats
 

Stud Size (mm)	Nut AF (mm)	Stud Size (ins)	Nut AF Heavy (ins)	Stud Size (ins)	Nut AF Regular (ins)
12	19			1/2	3/4
		1/2	7/8
16	24			5/8	15/16
		5/8	1 1/16
				3/4	1 1/8
20	30
		3/4	1 1/4
				7/8	1 5/16
24	36
		7/8	1 7/16
				1	1 1/2
27	41	1	1 5/8
				1 1/8	1 11/16
30	46	1 1/8	1 13/16
				1 1/4	1 7/8
33	50
		1 3/8	2 3/16
				1 1/2	2 1/4
39	60	1 1/2	2 3/16
				1 5/8	2 7/16
42	65	1 5/8	2 9/16
				1 3/4	2 5/8
45	70	1 3/4	2 3/4
				1 7/8	2 13/16
48	75	1 7/8	2 15/16
				2	3
		2	3 1/8
52	80
56	85
				2 1/4	3 3/8
		2 1/4	3 1/2