Hexagon Head Bolt M8*25mm

The Hexagon Head Bolt (often called hex bolt) is a standard, high-strength fastener with a six-sided (hexagonal) head and external machine threads. It is designed to mate with nuts or pre-tapped holes, delivering reliable clamping force for assembling two or more components, and is widely recognized for easy installation/removal via wrenches or socket tools.

Hexagon Head Bolt M8*25mm Core Design Features:

The hexagonal head provides maximum torque transmission, ensuring secure tightening; external machine threads (available in coarse [UNC] or fine [UNF] pitches) enable precise mating with nuts/threads; most variants have a plain shank (smooth section between head and threads) to reduce friction during installation.

Hexagon Head Bolt M8*25mm dimension and size:

THREAD SIZE D		M16	M20	(M22)	M24	(M27)	M30	M36
P Pitch of thread		2	2.5	2.5	3	3	3.5	4
bref for length / Nom <100/>100		31	36	38	41	44	49	56
bref for length / Nom <100/>100		38	43	45	48	51	56	63
c	Max	0.8	0.8	0.8	0.8	0.8	0.8	0.8
c	Min	0.4	0.4	0.4	0.4	0.4	0.4	0.4
dₐ	Max	18.7	23.24	25.24	27.64	31.24	34.24	41
dₛ	Max	16.7	20.84	22.84	24.84	27.84	30.84	37
dₛ	Min	15.3	19.16	21.16	23.16	26.16	29.16	35
dw	Max	†	†	†	†	†	†	†
dw	Min	24.9	31.4	33.3	38	42.8	46.5	55.9
e	Min	29.56	37.29	39.55	45.2	50.85	55.37	66.44
k	Nom	10	12.5	14	15	17	18.7	22.5
	Max	10.75	13.4	14.9	15.9	17.9	19.75	23.55
	Min	9.23	11.6	13.1	14.1	16.1	17.65	21.45
k’	Min	6.5	8.1	9.2	9.9	11.3	12.4	15
r – Min	Min	0.6	0.8	0.8	1	1.2	1.2	1.5
s	Max	27	34	36	41	46	50	60
s	Min	26.16	33	35	40	45	49	58.8
Chamfer length z	Max	3	3.8	3.8	4.5	4.5	5.3	6
Note-Sizes shown in brackets are at second preference, * For galvanized bolts, dimension apply before galvanizing. †dw’ Max = s actual.