Button Head screw also known as Button Socket Cap Screws are high-strength fasteners with an Internal Hex or Allen drive style with a wider bearing surface head. Button Socket Screws provide a more visually aesthetic appearance and are used in mechanical applications. Socket button head cap screws are mostly used when the need for reducing the size of equipment arises. The critical characteristic feature of these screws is the wide load-bearing surface. This particular quality makes it resistant to looseness. They are mostly used in the designing of compartments in the overhead space of a house. An essential expectation from those spaces is the ability to provide more space with limited hardware. To assist in the better assembly of all the parts, these screws also come with a wide cross-section.

The Difference Between Pan Head Screws And Button Head Screws. Button head screws have chamfered sides that curve all the way down to the bottom of the screw head. They have a slightly domed top but they do not have straight sides like pan head screws.

DIN 34805-1 – 2018 Button head screws – Driving feature hexalobular socket

Thread Size （d)		M3	M4	M5	M6	M8	M10	M12
P	Pitch	0.5	0.7	0.8	1	1.25	1.5	1.75
b	Ref.	18	20	22	24	28	32	36
da	max	3.6	4.7	5.7	6.8	9.2	11.2	13.7
dk	max	5.7	7.6	9.5	10.5	14	17.5	21
	min	5.4	7.24	9.14	10.07	13.57	17.07	20.48
d1	Ref.	3.5	4.9	5.6	7	9.9	11.2	14.2
ds	max	3	4	5	6	8	10	12
	min	2.86	3.82	4.82	5.82	7.78	9.78	11.73
dw	min	4.97	6.66	8.41	9.26	12.48	15.7	18.85
k	max	1.8	2.45	3	3.3	4.5	5.5	6.6
	min	1.6	2.25	2.7	3	4.2	5.2	6.24
R	max	3.5	4.6	5.6	6.2	7.6	10.1	11.8
	min	2.5	3.4	4.4	5	6.2	8.5	10
r1	min	0.1	0.2	0.2	0.25	0.4	0.4	0.6
r2	min	0.3	0.4	0.45	0.5	0.7	0.7	1.1
Socket No.		10	20	25	30	45	50	55
A	Ref.	2.8	3.95	4.5	5.6	7.93	8.95	11.35
t	max	0.93	1.53	1.61	1.78	2.54	3.05	3.8
	min	0.8	1.24	1.32	1.48	2.15	2.65	3.35
Length of Thread b		–	–	–	–	–	–	–

①,r1: Below the head radius for screws with thread-free.
②,r2：Shank lower head radius for screws with thread up to the head.

DIN 34805-2 – 2018 Button Head Screws – Screws With Collar and Driving Feature Hexalobular Socket

Thread Size(d)		M3	M4	M5	M6	M8	M10	M12
P	Pitch	0.5	0.7	0.8	1	1.25	1.5	1.75
dc	max	6.9	9.4	11.8	13.6	17.8	21.9	26
	min	6.32	8.82	11.1	12.9	17.1	21.06	25.16
ds	max	3	4	5	6	8	10	12
	min	2.86	3.82	4.82	5.82	7.78	9.78	11.73
k	max	1.8	2.45	3	3.3	4.5	5.5	6.6
	min	1.6	2.25	2.7	3	4.2	5.2	6.24
Socket No.		10	20	25	30	45	50	55
A	Ref.	2.8	3.95	4.5	5.6	7.93	8.95	11.35
t	max	0.93	1.53	1.61	1.78	2.54	3.05	3.8
	min	0.8	1.24	1.32	1.48	2.15	2.65	3.35
Length of Thread b	Ref.	–	–	–	–	–	–	–

ISO 7380 – 2004 Hexagon Socket Button Head Screws

Thread Size(d)		M3	M4	M5	M6	M8	M10	M12	M16
P	Pitch	0.5	0.7	0.8	1	1.25	1.5	1.75	2
a	max	1	1.4	1.6	2	2.5	3	3.5	4
	min	0.5	0.7	0.8	1	1.25	1.5	1.75	2
dk	max	5.7	7.6	9.5	10.5	14	17.5	21	28
	min	5.4	7.24	9.14	10.07	13.57	17.07	20.48	27.48
e ①	min	2.303	2.873	3.443	4.583	5.723	6.863	9.149	11.429
k	max	1.65	2.2	2.75	3.3	4.4	5.5	6.6	8.8
	min	1.4	1.95	2.5	3	4.1	5.2	6.24	8.44
s ①	Nominal Size	2	2.5	3	4	5	6	8	10
	max	2.08	2.58	3.08	4.095	5.14	6.14	8.175	10.175
	min	2.02	2.52	3.02	4.02	5.02	6.02	8.025	10.025
t	min	1.04	1.3	1.56	2.08	2.6	3.12	4.16	5.2
Minimum tensile load(N) ②	8.8	3220	5620	9080	12900	23400	37100	53900	100000
	10.9	4180	7300	11800	16700	30500	48200	70200	130000
	12.9	4910	8506	13800	19600	35700	56600	82400	154000

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