Property Class 8.8 Steel Low Head Socket Cap Screws (DIN 6912) are supplied to ISO 898-1 property class 8.8. Corrosion behaviour is requires plating (zinc) for corrosion protection, the material is magnetic, and the usable service range is commonly limited to approx. +300 °C; confirm against the coating and the load. In practice this grade is the workhorse medium-carbon alloy class for structural joints.
- Grade
- ISO 898-1 property class 8.8
- Corrosion resistance
- Requires plating (zinc) for corrosion protection
- Magnetic response
- Magnetic
- Service temperature
- commonly limited to approx. +300 °C; confirm against the coating and the load
Property values are typical for the grade. Certified mechanical test data is available on request for production orders.
Property Class 8.8 Steel Low Head Socket Cap Screws (DIN 6912) are supplied to DIN 6912. The grade provides requires plating (zinc) for corrosion 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 8.8 Steel for Low Head Socket Cap Screws (DIN 6912)
The workhorse medium-carbon alloy class for structural joints. For low head socket cap screws (din 6912), this matters when requires plating (zinc) for corrosion protection is the primary requirement.
Mechanical & Physical Properties
| Grade designation | ISO 898-1 property class 8.8 |
|---|
| Magnetic response | Magnetic |
|---|
| Service temperature | commonly limited to approx. +300 °C; confirm against the coating and the load |
|---|
| Corrosion characteristic | Requires plating (zinc) for corrosion protection |
|---|
Corrosion Behavior in Service
Carbon and alloy steel low head socket cap screws (din 6912) 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 (din 6912) 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 (DIN 6912) Available in Property Class 8.8 Steel
| Thread size | Pitch (mm) | Head diameter dk (mm) | Head height k (mm) | Hex socket s (mm) | Socket depth t (mm) | Max torque vs DIN 912 | Reference standard |
|---|
| M3 | 0.5 | 5.5 | 2.0 | 2.0 | 1.2 | approx. 60% | DIN 6912 |
| M4 | 0.7 | 7.0 | 2.6 | 2.5 | 1.5 | approx. 60% | DIN 6912 |
| M5 | 0.8 | 8.5 | 3.2 | 3.0 | 1.8 | approx. 60% | DIN 6912 |
| M6 | 1.0 | 10.0 | 3.8 | 4.0 | 2.2 | approx. 65% | DIN 6912 |
| M8 | 1.25 | 13.0 | 5.0 | 5.0 | 2.8 | approx. 65% | DIN 6912 |
| M10 | 1.5 | 16.0 | 6.0 | 6.0 | 3.5 | approx. 65% | DIN 6912 |
| M12 | 1.75 | 18.0 | 7.0 | 8.0 | 4.4 | approx. 70% | DIN 6912 |
Dimensions are independent of the material: every size above is available in Property Class 8.8 Steel.
Custom manufacturing · Made to drawing
Need this screw in a grade that is not listed?
Grade 8 8 Steel is one of the grades the catalog describes. Lengths and thread lengths outside the standard table are the commonest request, followed by a drive the standard does not offer and a head marked with your own part number. Made by cold heading or warm forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
Custom screw manufacturingSend a drawing
Applications & Industries
Low Head Socket Cap Screws are bought for a small number of well-defined jobs. These are the ones we ship them for. Stocked from M3 to M12.
Industries that specify Low Head Socket Cap Screws
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Machine tools & fixtures
Counterbores too shallow for a standard cap screw.
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Mould & die making
Fixings in plates where depth is at a premium.
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Robotics & automation
Compact joints in moving assemblies.
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Energy & infrastructure
Tower, pipework, switchgear and plant fixings specified for long service life and inspectable joints.
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Maintenance & MRO
Stocked replacements matched to an existing property class, thread and finish.
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Food, pharma & cleanroom
Stainless assemblies that are washed down, where the finish matters as much as the strength.
Typical applications
- where a standard DIN 912 head would stand proud
- fixings in a shallow counterbore
- joints where the property class is stated on the drawing
- clamping two machined faces to a calculated preload
- bolting brackets, motors and gearboxes to a frame
- assemblies that are dismantled for service and re-torqued
Service conditions to specify against
- Marine and coastal
- Available in A4 (316) stainless for chloride exposure — coastal structures, pool halls, water treatment and deck hardware, where A2 will eventually pit.
- High load
- Supplied in ISO 898-1 property classes, so the joint can be designed to a stated proof load and tightened to a calculated torque rather than by feel.
- Torque and preload
- The joint is designed around bolt tension, so lubrication, coating and the friction coefficient all change the torque figure — state them together.
Where to use something else
- The smaller socket takes less torque than a standard cap screw — do not substitute one into a joint torqued for DIN 912.
- Do not use a machine thread into unthreaded sheet or timber; use a tapping screw, rivet nut or insert made for that parent material.
Full application guide: where Low Head Socket Cap Screws are used, how to specify them, and the cases they are wrong for
