Property Class 12.9 Steel Low Head Socket Cap Screws are supplied to DIN 7984. The grade provides requires plating or black-oxide protection and is magnetic; the practical service range is commonly limited to approx. +300 °C; confirm against the coating and the load. Property data, grade comparison and the full size table follow.
Why Choose Property Class 12.9 Steel for Low Head Socket Cap Screws
The highest common strength class, for high-load machine assembly. For low head socket cap screws, this matters when requires plating or black-oxide protection is the primary requirement.
Mechanical & Physical Properties
| Grade designation | ISO 898-1 property class 12.9 |
|---|---|
| Magnetic response | Magnetic |
| Service temperature | commonly limited to approx. +300 °C; confirm against the coating and the load |
| Corrosion characteristic | Requires plating or black-oxide protection |
Corrosion Behavior in Service
Carbon and alloy steel low head socket cap screws require a coating for corrosion protection. Zinc plating (with or without passivation) is the most common; hot-dip galvanizing is used for outdoor structural service; black-oxide is mainly a tarnish-prevention finish for tool-room use.
Galvanic & Galling Considerations
For low head socket cap screws in steel, the dominant compatibility issue is hydrogen embrittlement at high property classes (10.9 and above) when electroplated. Plating must be followed by an appropriate baking treatment, or a non-electroplated finish (mechanical zinc, zinc flake) should be substituted.
Sizes of Low Head Socket Cap Screws Available in Property Class 12.9 Steel
| Size | Pitch P (mm) | b (mm) | Head diameter dk (mm) | da (mm) | ds_min (mm) | e (mm) | Head height k (mm) | r (mm) | Hex socket s (mm) | t (mm) | v (mm) | dw (mm) | Length range l (mm) | Reference standard |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| M3 | 0.5 | 12 | 5.5 | 3.6 | 2.86 | 2.3 | 2.0 | 0.1 | 2.0 | 1.5 | 0.3 | 4.84 | 5~20 | DIN 7984 |
| M4 | 0.7 | 14 | 7.0 | 4.7 | 3.82 | 2.87 | 2.8 | 0.2 | 2.5 | 2.3 | 0.4 | 6.2 | 6~25 | DIN 7984 |
| M5 | 0.8 | 16 | 8.5 | 5.7 | 4.82 | 3.44 | 3.5 | 0.2 | 3.0 | 2.7 | 0.5 | 7.7 | 8~30 | DIN 7984 |
| M6 | 1.0 | 18 | 10.0 | 6.8 | 5.82 | 4.58 | 4.0 | 0.25 | 4.0 | 3.0 | 0.6 | 9.2 | 10~40 | DIN 7984 |
| M8 | 1.25 | 22 | 13.0 | 9.2 | 7.7 | 5.72 | 5.0 | 0.4 | 5.0 | 3.8 | 0.8 | 12.03 | 12~60 | DIN 7984 |
| M10 | 1.5 | 26 | 16.0 | 11.2 | 9.78 | 8.01 | 6.0 | 0.4 | 7.0 | 4.5 | 1.0 | 15.03 | 16~70 | DIN 7984 |
| M12 | 1.75 | 30 | 18.0 | 13.7 | 11.73 | 9.15 | 7.0 | 0.6 | 8.0 | 5.0 | 1.2 | 17.03 | 20~80 | DIN 7984 |
| (M14) | 2.0 | 34 | 21.0 | 15.7 | 13.73 | 11.43 | 8.0 | 0.6 | 10.0 | 5.3 | 1.4 | 19.83 | 30~80 | DIN 7984 |
| M16 | 2.0 | 38 | 24.0 | 17.7 | 15.73 | 13.72 | 9.0 | 0.6 | 12.0 | 5.5 | 1.6 | 22.83 | 30~80 | DIN 7984 |
| (M18) | 2.5 | 42 | 27.0 | 20.2 | 17.73 | 13.72 | 10.0 | 0.6 | 12.0 | 6.5 | 1.8 | 25.83 | 40~100 | DIN 7984 |
| M20 | 2.5 | 46 | 30.0 | 22.4 | 19.67 | 16.0 | 11.0 | 0.8 | 14.0 | 7.5 | 2.0 | 28.83 | 40~100 | DIN 7984 |
| (M22) | 2.5 | 50 | 33.0 | 24.4 | 21.67 | 16.0 | 12.0 | 0.8 | 14.0 | 8.0 | 2.2 | 31.61 | 50~100 | DIN 7984 |
| M24 | 3.0 | 54 | 36.0 | 26.4 | 23.67 | 19.44 | 13.0 | 0.8 | 17.0 | 8.0 | 2.4 | 34.61 | 50~100 | DIN 7984 |
Dimensions are independent of the material: every size above is available in Property Class 12.9 Steel.
Custom manufacturing · Made to drawing
Need this screw in a grade that is not listed?
Grade 12 9 Steel is one of the grades the catalog describes. Head form and drive can be specified to the assembly rather than to a standard: a larger bearing face, a security drive, or a socket sized for the tool already on the bench. Made by cold heading or warm forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
