DIN 7985 Screw with Cylinder Head and Hemispherical Top

The DIN 7985 screw with cylinder head and hemispherical top is a fastener of property class 4.8, made from carbon steel grades St.10 and St.10kp.

Properties of class 4.8

• Tensile strength of the material — 400 N/mm²
• Yield strength — 320 N/mm²

How to choose a DIN 7985 4.8 screw

When choosing, consider:

• thread diameter,
• recess type (cross recess PH/PZ or Torx),
• presence of anti-corrosion coating,
• compliance with GOST or DIN.

The round head simplifies installation and reduces the risk of self-loosening. PH, PZ or Torx recesses ensure reliable tool engagement, including in confined spaces.

Applications

DIN 7985 4.8 screws are used in household and engineering applications and combine with other fasteners. The hemispherical head shape gives the joint a neat appearance.

DIN 7985 4.8 screw compliance table

Product	Property class	Nominal tensile strength (N/mm²)	Yield strength (MPa)	Vickers hardness, HV	Steel grade	Characteristics
DIN 7985 screw	4.8	400-420	320-340	130 – 250	St.10, St.10kp	Carbon steel (carbon content below 0.55%)

Dimension table for DIN 7985 (ISO 7045) cylinder head screws with cross recess, mm

d		M1.6	M2	M2.5	M3	M3.5	M4	M5	M6	M8	M10
P		0.35	0.4	0.45	0.5	0.6	0.7	0.8	1	1.25	1.5
d1	DIN 7985	3.2	4	5	6	7	8	10	12	16	20
	ISO 7045				5.6			9.5
k	DIN 7985	1.3	1.6	2	2.4	2.7	3.1	3.8	4.6	6	7.5
	ISO 7045			2.1		2.6		3.7
m		0	1	1	1	1	2	2	3	4	4
l	min.	3	3	3	4	5	5	6	8	10	12
	max.	16	20	25	30	35	40	50	60	60	60

Designations:

d - nominal thread diameter

P - thread pitch

d1 - head diameter

k - head height

m - PH or PZ cross recess size

l - screw length

Comparison table of DIN 7985 and GOST 17473-80 standards

Parameter	DIN 7985	GOST 17473-80
d - nominal thread diameter, mm	1.5 to 10	1 to 20
P - thread pitch, mm	0.35 to 1.5	coarse - 0.25 to 2.5 fine - 1 to 1.5 (for d=8-20)
b - thread length, mm	15 to 40	8 to 70
d1 - head diameter, mm	3.2 to 20	2 to 30
k - head height, mm	1.3 to 7.5	0.7 to 14
l - length, mm	2 to 60	2 to 120
Product grade	A	A and B
Screwdriver recess type	cross recess PH or PZ	slot or cross recess