ASME B18.2.3.1m Metric Hex Cap Screws

Nominal Screw Dia.,D,and Thread Pitch	Body Dia., D _s		Width Across Flats, S		Width Across Corners, E		Head Height, K		Wrenching Height, K1 ₁	Washer Face Thick., C		Washer Face Dia., D_W
Nominal Screw Dia.,D,and Thread Pitch	Max	Min	Max	Min	Max	Min	Max	Min	Min	Max	Min	Min
ANSI B18.2.3.1M - M5 × 0.8	5	4.82	8	7.78	9.24	8.79	3.65	3.35	2.4	0.5	0.2	7
ANSI B18.2.3.1M - M6 × 1	6	5.82	10	9.78	11.55	11.05	4.15	3.85	2.8	0.5	0.2	8.9
ANSI B18.2.3.1M - M8 × 1.25	8	7.78	13	12.73	15.01	14.38	5.5	5.1	3.7	0.6	0.3	11.6
ANSI B18.2.3.1M - ^aM10× 1.5	10	9.78	15	14.73	17.32	16.64	6.63	6.17	4.5	0.6	0.3	13.6
ANSI B18.2.3.1M - M10 × 1.5	10	9.78	16	15.73	18.48	17.77	6.63	6.17	4.5	0.6	0.3	14.6
ANSI B18.2.3.1M - M12 × 1.75	12	11.73	18	17.73	20.78	20.03	7.76	7.24	5.2	0.6	0.3	16.6
ANSI B18.2.3.1M - M14 × 2	14	13.73	21	20.67	24.25	23.35	9.09	8.51	6.2	0.6	0.3	19.6
ANSI B18.2.3.1M - M16 × 2	16	15.73	24	23.67	27.71	26.75	10.32	9.68	7	0.8	0.4	22.5
ANSI B18.2.3.1M - M20 × 2.5	20	19.67	30	29.16	34.64	32.95	12.88	12.12	8.8	0.8	0.4	27.7
ANSI B18.2.3.1M - M24 × 3	24	23.67	36	35	41.57	39.55	15.44	14.56	10.5	0.8	0.4	33.2
ANSI B18.2.3.1M - M30 × 3.5	30	29.67	46	45	53.12	50.85	19.48	17.92	13.1	0.8	0.4	42.7
ANSI B18.2.3.1M - M36 × 4	36	35.61	55	53.8	63.51	60.79	23.38	21.62	15.8	0.8	0.4	51.1
ANSI B18.2.3.1M - M42 × 4.5	42	41.38	65	62.9	75.06	71.71	26.97	25.03	18.2	1	0.5	59.8
ANSI B18.2.3.1M - M48 × 5	48	47.38	75	72.6	86.6	82.76	31.07	28.93	21	1	0.5	69
ANSI B18.2.3.1M - M56 × 5.5	56	55.26	85	82.2	98.15	93.71	36.2	33.8	24.5	1	0.5	78.1
ANSI B18.2.3.1M - M64 × 6	64	63.26	95	91.8	109.7	104.65	41.32	38.68	28	1	0.5	87.2
ANSI B18.2.3.1M - M72 × 6	72	71.26	105	101.4	121.24	115.6	46.45	43.55	31.5	1.2	0.6	96.3
ANSI B18.2.3.1M - M80 × 6	80	79.26	115	111	132.72	126.54	51.58	48.42	35	1.2	0.6	105.4
ANSI B18.2.3.1M - M90 × 6	90	89.13	130	125.5	150.11	143.07	57.74	54.26	39.2	1.2	0.6	119.2
ANSI B18.2.3.1M - M100 × 6	100	99.13	145	140	167.43	159.6	63.9	60.1	43.4	1.2	0.6	133
(a) This size with width across flats of 15 mm is not standard. Unless specifically ordered, M10 hex cap screws with 16 mm width across flats will be furnished. All dimensions are in millimeters. Basic thread lengths, B, are the same as given in . Transition thread length, X, includes the length of incomplete threads and tolerances on grip gaging length and body length. It is intended for calculation purposes. For additional manufacturing and acceptance specifications, reference should be made to the ASME B18.2.3.1M-1979 (R1995).