ASME B18.3.1m Socket Head Cap Screws

Nom. Sizeand Thread Pitch	Body Diameter, D		Head Diameter A		Head Height H		Chamferor Radius S	Hexagon Socket Size^a J	Spline Socket Size^a M	Key Engagement T	Transition Dia. B ^a
Nom. Sizeand Thread Pitch	Max	Min	Max	Min	Max	Min	Max	Nom.	Nom.	Min	Max
ASME B18.3.1M - M1.6 × 0.35	1.6	1.46	3	2.87	1.6	1.52	0.16	1.5	1.829	0.8	2
ASME B18.3.1M - M2 × 0.4	2	1.86	3.8	3.65	2	1.91	0.2	1.5	1.829	1	2.6
ASME B18.3.1M - M2.5 × 0.45	2.5	2.36	4.5	4.33	2.5	2.4	0.25	2	2.438	1.25	3.1
ASME B18.3.1M - M3 × 0.5	3	2.86	5.5	5.32	3	2.89	0.3	2.5	2.819	1.5	3.6
ASME B18.3.1M - M4 × 0.7	4	3.82	7	6.8	4	3.88	0.4	3	3.378	2	4.7
ASME B18.3.1M - M5 × 0.8	5	4.82	8.5	8.27	5	4.86	0.5	4	4.648	2.5	5.7
ASME B18.3.1M - M6 × 1	6	5.82	10	9.74	6	5.85	0.6	5	5.486	3	6.8
ASME B18.3.1M - M8 × 1.25	8	7.78	13	12.7	8	7.83	0.8	6	7.391	4	9.2
ASME B18.3.1M - M10 × 1.5	10	9.78	16	15.67	10	9.81	1	8	...	5	11.2
ASME B18.3.1M - M12 × 1.75	12	11.73	18	17.63	12	11.79	1.2	10	...	6	14.2
ASME B18.3.1M - M14 × 2^b	14	13.73	21	20.6	14	13.77	1.4	12	...	7	16.2
ASME B18.3.1M - M16 × 2	16	15.73	24	23.58	16	15.76	1.6	14	...	8	18.2
ASME B18.3.1M - M20 × 2.5	20	19.67	30	29.53	20	19.73	2	17	...	10	22.4
ASME B18.3.1M - M24 × 3	24	23.67	36	35.48	24	23.7	2.4	19	...	12	26.4
ASME B18.3.1M - M30 × 3.5	30	29.67	45	44.42	30	29.67	3	22	...	15	33.4
ASME B18.3.1M - M36 × 4	36	35.61	54	53.37	36	35.64	3.6	27	...	18	39.4
ASME B18.3.1M - M42 × 4.5	42	41.61	63	62.31	42	41.61	4.2	32	...	21	45.6
ASME B18.3.1M - M48 × 5	48	47.61	72	71.27	48	47.58	4.8	36	...	24	52.6
a See also Table 25. b The M14 ×2 size is not recommended for use in new designs. All dimensions are in millimeters LG is grip length and LB is body length. For length of complete thread. For additional manufacturing and acceptance specifications, see ASME B18.3.1M-1986.