ASME B18.2.3.5M Metric Hex Bolts Dimensions

Nominal Bolt Diameter, D, and Thread Pitch	Body Diameter D_s		Width Across Flats, S		Width Across Corners, E		Head Height, K		Wrenching Height, K1, Min	For Bolt Lengths Basic Thread Length, ^a B
Nominal Bolt Diameter, D, and Thread Pitch	Max	Min	Max	Min	Max	Min	Max	Min	Wrenching Height, K1, Min	< 125mm	> 125 and < 200mm	> 200mm
M5 x 0.8	5.48	4.52	8.00	7.64	9.24	8.63	3.58	3.35	2.4	16	22	35
M6 x 1	6.19	5.52	10.00	9.64	11.55	10.89	4.38	3.55	2.8	18	24	37
M8 x 1.25	8.58	7.42	13.00	12.57	15.01	14.20	5.68	5.10	3.7	22	28	41
^aM10 x 1.5	10.58	9.42	15.00	14.57	17.32	16.46	6.85	6.17	4.5	26	32	45
M10 x 1.5	10.58	9.42	16.00	15.57	18.48	17.59	6.85	6.17	4.5	26	32	45
M12 x 1.75	12.70	11.30	18.00	17.57	20.78	19.85	7.95	7.24	5.2	30	36	49
M14 x 2	14.70	13.30	21.00	20.16	24.25	22.78	9.25	8.51	6.2	34	40	53
M16 x 2	16.70	15.30	24.00	23.16	27.71	26.17	10.75	9.68	7.0	38	44	57
M20 x 2.5	20.84	19.16	30.00	29.16	34.64	32.95	13.40	12.12	8.8	46	52	65
M24 x 3	24.84	23.16	36.00	35.00	41.57	39.55	15.90	14.56	10.5	54	60	73
M30 x 3.5	30.84	29.16	46.00	45.00	5312	50.55	19.78	17.92	13.1	66	72	85
M36 x 4	37.00	35.00	55.00	53.80	63.51	60.79	23.55	21.72	15.8	78	84	97
M42 x 4.5	43.00	41.00	65.00	62.90	75.06	71.71	27.05	25.03	18.2	90	96	109
M48 x 5	49.00	47.00	75.00	72.60	86.60	82.76	31.07	28.93	21.0	102	108	121
M56 x 5.5	57.20	54.80	85.00	82.20	98.15	93.71	36.20	33.80	24.5	—	124	137
M64 x 6	65.52	62.80	95.00	91.80	109.70	104.65	41.32	38.68	28.0	—	140	153
M72 x 6	73.84	70.80	105.00	101.40	121.24	115.60	46.45	43.55	31.5	—	156	169
M80 x 6	82.16	78.80	115.00	111.00	132.79	126.54	51.58	48.42	35.0	—	172	185
M90 x 6	92.48	88.60	130.00	125.50	150.11	143.07	57.74	54.26	39.2	—	192	205
M100 x 6	102.80	98.60	145.00	140.00	167.43	159.60	63.90	60.10	43.4	—	212	225