Socket Head Cap Screw
Dimensions and Specifications

Head and Body Dimensions - Alloy and Stainless
ASME B18.3-1998 - Includes 1960 Series

Screw Diam.	D		A		H		C	J	F		T	G	K
	Body Diameter		Head Diameter		Head Height		Top Chamfer or Radius	Hex Socket Size	Fillet Transition Diameter		Key Engage- ment	Wall Thick- ness	Bottom Chamfer or Radius
0	.0600	.0568	.0960	.091	.060	.057	.004	.050	.074	.063	.025	.020	.007
1	.0730	.0695	.118	.112	.073	.070	.005	1/16	.087	.076	.031	.025	.007
2	.0860	.0822	.140	.134	.086	.083	.008	5/64	.102	.090	.038	.029	.007
3	.0990	.0949	.161	.154	.099	.095	.008	5/64	.115	.103	.044	.034	.007
4	.1120	.1075	.183	.176	.112	.108	.009	3/32	.130	.118	.051	.038	.008
5	.1250	.1202	.205	.198	.125	.121	.012	3/32	.145	.132	.057	.043	.008
6	.138	.1329	.226	.218	.138	.134	.013	7/64	.158	.145	.064	.047	.008
8	.1640	.1585	.270	.262	.164	.159	.014	9/64	.188	.173	.077	.056	.008
10	.1900	.1840	.312	.303	.190	.185	.018	5/32	.218	.202	.090	.065	.008
1/4	.2500	.2435	.375	.365	.250	.244	.025	3/16	.278	.262	.120	.095	.010
5/16	.3125	.3053	.469	.457	.312	.306	.033	1/4	.347	.329	.151	.119	.010
3/8	.3750	.3678	.562	.550	.375	.368	.040	4/15	.415	.398	.182	.143	.010
7/16	.4375	.4294	.656	.642	.438	.430	.047	3/8	.484	.465	.213	.166	.015
1/2	.5000	.4919	.750	.735	.500	.492	.055	3/8	.552	.532	.245	.190	.015
5/8	.6250	.6163	.938	.921	.625	.616	.070	1/2	.689	.664	.307	.238	.015
3/4	.7500	.7406	1.125	1.107	.750	.740	.085	5/8	.828	.801	.370	.285	.015
7/8	.8750	.8647	1.312	1.293	.875	.864	.100	3/4	.963	.933	.432	.333	.020
1	1.0000	.9886	1.500	1.479	1.000	.988	.114	3/4	1.100	1.069	.495	.380	.020
1-1/4	1.2500	1.2336	1.875	1.852	1.250	1.236	.144	7/8	1.370	1.334	.620	.475	.020
1-1/2	1.5000	1.4818	2.250	2.224	1.500	1.485	.176	1	1.640	1.602	.745	.570	.020

Length Specifications - Alloy and Stainless
ASME B18.3-1998 - Includes 1960 Series

Nominal Size D	0		1		2		3		4		5		6		8		10
Basic Thread Length LT	.500		.625		.625		.625		.750		.750		.750		.875		.875
Nominal Length L	LG	LB	LG	LB	LG	LB	LG	LB	LG	LB	LG	LB	LG	LB	LG	LB	LG	LB
1.00	.50	.44	.25	.17	.25	.16	.25	.15	.25	.12	.25	.12
1.25	.75	.69	.62	.55	.62	.54	.62	.52	.25	.12	.25	.12	.50	.34	.38	.22	.38	.17
1.50			.88	.80	.88	.79	.88	.77	.75	.62	.75	.62	.50	.34	.38	.22	.38	.17
1.75					1.12	1.04	1.12	1.02	.75	.62	.75	.62	1.00	.84	.88	.72	.88	.67
2.00							1.38	1.27	1.25	1.12	1.25	1.12	1.00	.84	.88	.72	.88	.67
2.25									1.25	1.12	1.25	1.12	1.50	1.34	1.38	1.22	1.38	1.17
2.50											1.75	1.62	1.50	1.34	1.38	1.22	1.38	1.17
2.75													2.00	1.84	1.88	1.72	1.88	1.67
3.00															1.88	1.72	1.88	1.67
3.50																	2.38	2.17

Length Specifications - Alloy and Stainless
ASME B18.3-1998 - Includes 1960 Series

Nominal Size D	1/4		5/16		3/8		7/16		1/2		5/8		3/4		7/8		1
Basic Thread Length LT	1.000		1.125		1.250		1.375		1.500		1.750		2.000		2.250		2.500
Nominal Length L	LG	LB	LG	LB	LG	LB	LG	LB	LG	LB	LG	LB	LG	LB	LG	LB	LG	LB
1.50	.50	.25
1.75	.50	.25	.62	.35	.50	.19
2.00	1.00	.75	.62	.35	.50	.19	.62	.27
2.25	1.00	.75	1.12	.85	1.00	.69	.62	.27	.75	.36
2.50	1.50	1.25	1.12	.85	1.00	.69	1.12	.77	.75	.36	.75	.30
2.75	1.50	1.25	1.62	1.35	1.50	1.19	1.12	.77	.75	.36	.75	.30
3.00	2.00	1.75	1.62	1.35	1.50	1.19	1.62	1.27	1.50	1.12	.75	.30	1.00	.50
3.25	2.00	1.75	2.12	1.85	2.00	1.69	1.62	1.27	1.50	1.12	1.50	1.04	1.00	.50	1.00	.44
3.50	2.50	2.25	2.12	1.85	2.00	1.69	2.12	1.77	1.50	1.12	1.50	1.04	1.00	.50	1.00	.44	1.00	.38
4.00	3.00	2.75	2.62	2.35	2.50	2.19	2.62	2.27	2.25	1.86	2.25	1.80	2.00	1.50	1.00	.44	1.00	.38
4.50	3.50	3.25	3.12	2.85	3.00	2.69	3.12	2.77	3.00	2.62	2.25	1.80	2.00	1.50	2.00	1.44	2.00	1.38
5.00	4.00	3.75	3.62	3.35	3.50	3.09	3.62	3.27	3.00	2.62	3.00	2.54	3.00	2.50	2.00	1.44	2.00	1.38
5.50			4.12	3.85	4.00	3.69	4.12	3.77	3.75	3.36	3.75	3.30	3.00	2.50	3.00	2.44	3.00	2.38
6.00			4.62	4.35	4.50	4.19	4.62	4.27	4.50	4.12	3.75	3.30	4.00	3.50	3.00	2.44	3.00	2.38
6.50					5.00	4.69	5.12	4.77	4.50	4.12	4.50	4.04	4.00	3.50	4.00	3.44	4.00	3.38
7.00					5.50	5.19	5.62	5.27	5.25	4.86	5.25	4.80	5.00	4.50	4.00	3.44	4.00	3.38
8.00							6.62	6.27	6.00	5.62	6.00	5.54	6.00	5.50	5.00	4.44	5.00	4.38
9.00							7.62	7.27	7.00	6.62	6.75	6.30	7.00	6.50	6.00	5.44	6.00	5.38
10.00									8.00	7.62	7.75	7.30	8.00	7.50	7.00	6.44	7.00	6.38
11.00											9.25	8.80	9.00	8.50	8.00	7.44	8.00	7.38
12.00											10.25	9.80	10.00	9.50	9.00	8.44	9.00	8.38

Notes pertaining to the Thread length of Socket Head Cap Screws

The basic thread lengths (LT) listed directly below the nominal sizes in the above two tables represents the nominal length up to which all screws of that diameter shall be fully threaded. To determine the threaded portion of the screws with a nominal length greater than LT, subtract the minimum design grip length (LG from the nominal length (L). For screws over 1 inch in diameter and of nominal lengths longer than LT, the maximum grip gaging length (LG and the minimum body length (LB) of the screws shall be determined as follows. LG = L - LT LB = L - LTT Where: L = Nominal Length Where: LT = Minimum thread length tabulated below Where: LTT = Maximum total thread length tabulated below

Nominal Size	Min Thread Length (LT)	Max Total Thread Length (LTT)
1-1/4	3.12	5.09
1-1/2	3.75	6.08

Assembly Instructions

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