ASME B18.2.6M Heavy Hex Bolts

ASME B18.2.6M Standard covers the complete general and dimensional data for products in the metric series recognized as American National Standard for sizes M12 through M36. These four metric structural products include

• (a) metric heavy hex structural bolts: ASTM A325M and ASTM A490M
• (b) metric heavy hex nuts: ASTM A563M
• (c) metric hardened steel washers; circular, circular clipped, and beveled: ASTM F436M
• (d) metric compressible washer-type direct tension indicators: ASTM F959M

ASME B18.2.6M Heavy Hex Bolts Dimensions (mm)

Nominal Size	Body Diameter, E		AF, F		AC, G		Head Height, H		Fillet Radius, R	Thread Length, LT, Ref.	Transition Thread Length, Y, Ref.	Runout of Bearing Surface FIM
	Max.	Min.	Max.	Min.	Max.	Min.	Max.	Min.	Min.		Max.	Max.
M12 X 1.75	12.70	11.30	21.00	20.16	24.25	22.78	7.95	7.05	0.6	25.0	5.2	0.4
M16 X 2	16.70	15.30	27.00	26.16	31.18	29.56	10.75	9.25	0.6	31.0	6.0	0.5
M20 X 2.5	20.84	19.16	34.00	33.00	39.26	37.29	13.40	11.60	0.8	36.0	7.5	0.6
M22 X 2.5	22.84	21.16	36.00	35.00	41.57	39.55	14.90	13.10	0.8	38.0	7.5	0.6
M24 X 3	24.84	23.16	41.00	40.00	47.34	45.20	15.90	14.10	1.0	41.0	9.0	0.7
M27 X 3	27.84	26.16	46.00	45.00	53.12	50.85	17.90	16.10	1.2	44.0	9.0	0.8
M30 X 3.5	30.84	29.16	50.00	49.00	57.74	55.37	19.75	17.65	1.2	49.0	10.5	0.9
M36 X 4	37.00	35.00	60.00	58.80	69.28	66.44	23.55	21.45	1.5	56.0	12.0	1.0

ASME B18.2.6M Heavy Hex Bolts Length (mm)

Nominal Length, L	M12 X 1.75		M16 X 2		M20 X 2.5		M22 X 2.5		M24 X 3		M27 X 3		M30 X 3.5		M36 X 4
	LG	LS,	LG	LS,	LG	LS,	LG	LS,	LG	LS,	LG	LS,	LG	LS,	LG	LS,
	Max.	Min.	Max.	Min.	Max.	Min.	Max.	Min.	Max.	Min.	Max.	Min.	Max.	Min.	Max.	Min.
40	15	9.8	...	...	...	...	...	...	...	...	...	...	...	...	...	...
45	20	14.8	14	8	...	...	...	...	...	...	...	...	...	...	...	...
50	25	19.8	19	13	14	6.5	...	...	...	...	...	...	...	...	...	...
55	30	24.8	24	18	19	11.5	17	9.5	...	...	...	...	...	...	...	...
60	35	29.8	29	23	24	16.5	22	14.5	19	10	...	...	...	...	...	...
65	40	34.8	34	28	29	21.5	27	19.5	24	15	21	12	...	...	...	...
70	45	39.8	39	33	34	26.5	32	24.5	29	20	26	17	21	10.5	...	...
75	50	44.8	44	38	39	31.5	37	29.5	34	25	31	22	26	15.5	...	...
80	55	49.8	49	43	44	36.5	42	34.5	39	30	36	27	31	20.5	19	7
85	60	54.8	54	48	49	41.5	47	39.5	44	35	41	32	36	25.5	24	12
90	65	59.8	59	53	54	46.5	52	44.5	49	40	46	37	41	30.5	29	17
95	70	64.8	64	58	59	51.5	57	49.5	54	45	51	42	46	35.5	34	22
100	75	69.8	69	63	64	56.5	62	54.5	59	50	56	47	51	40.5	39	27
110	...	...	79	73	74	66.5	72	64.5	69	60	66	57	61	50.5	44	32
120	...	...	89	83	84	76.5	82	74.5	79	70	76	67	71	60.5	54	42
130	...	...	99	93	94	86.5	92	84.5	89	80	86	77	81	70.5	64	52
140	...	...	109	103	104	96.5	102	94.5	99	90	96	87	91	80.5	74	62
150	...	...	119	113	114	106.5	112	104.5	109	100	106	97	101	90.5	84	72
160	...	...	129	123	124	116.5	122	114.5	119	110	116	107	111	100.5	94	82
170	...	...	139	133	134	126.5	132	124.5	129	120	126	117	121	110.5	104	92
180	...	...	149	143	144	136.5	142	134.5	139	130	136	127	131	120.5	114	102
190	...	...	159	153	154	146.5	152	144.5	149	140	146	137	141	130.5	124	112
200	...	...	169	163	164	156.5	162	154.5	159	150	156	147	151	140.5	134	122
210	...	...	179	173	174	166.5	172	164.5	169	160	166	157	161	150.5	144	132
220	...	...	189	183	184	176.5	182	174.5	179	170	176	167	171	160.5	154	142
230	...	...	199	193	194	186.5	192	184.5	189	180	186	177	181	170.5	164	152
240	...	...	209	203	204	196.5	202	194.5	199	190	196	187	191	180.5	174	162
250	...	...	219	213	214	206.5	212	204.5	209	200	206	197	201	190.5	184	172
260	...	...	229	223	224	216.5	222	214.5	219	210	216	207	211	200.5	194	182
270	...	...	239	233	234	226.5	232	224.5	229	220	226	217	221	210.5	204	192
280	...	...	249	243	244	236.5	242	234.5	239	230	236	227	231	220.5	214	202
290	...	...	259	253	254	246.5	252	244.5	249	240	246	237	241	230.5	224	212
300	...	...	269	263	264	256.5	262	254.5	259	250	256	247	251	240.5	234	222