Property Class 8.8 Steel Pin-in-Torx Security Screws 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 Pin-in-Torx Security Screws combine the dimensional form of ISO 14583 with the material properties of grade ISO 898-1 property class 8.8: requires plating (zinc) for corrosion protection, magnetic, service range commonly limited to approx. +300 °C; confirm against the coating and the load. This page summarizes the grade data, its corrosion behavior in service, the comparable grades, and the sizes supplied.
Why Choose Property Class 8.8 Steel for Pin-in-Torx Security Screws
The workhorse medium-carbon alloy class for structural joints. For pin-in-torx security screws, 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 |
|---|
Galvanic & Galling Considerations
For pin-in-torx security 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.
Comparable Grades
For Pin-in-Torx Security Screws, class 10.9 or 12.9 is the comparable strength step. Move up when the joint preload approaches the proof load of the current class; move down when the joint is over-specified. For corrosion-critical service, switch to stainless A2 or A4.
Sizes of Pin-in-Torx Security Screws Available in Property Class 8.8 Steel
| Thread size | Pitch (mm) | Head diameter dk (mm) | Head height k (mm) | Drive | Security bit | Common length range (mm) | Reference standard |
|---|
| M3 | 0.5 | 5.6 | 2.4 | Pin-in-Torx | TR10 | 6~30 | ISO 14583 |
| M4 | 0.7 | 8.0 | 3.1 | Pin-in-Torx | TR20 | 8~40 | ISO 14583 |
| M5 | 0.8 | 9.5 | 3.7 | Pin-in-Torx | TR25 | 8~50 | ISO 14583 |
| M6 | 1.0 | 12.0 | 4.6 | Pin-in-Torx | TR30 | 10~60 | ISO 14583 |
| M8 | 1.25 | 16.0 | 6.0 | Pin-in-Torx | TR40 | 12~60 | ISO 14583 |
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
The sectors that buy Pin-in-Torx Security Screws to ISO 14583, and the duty each one buys them for. Stocked from M3 to M8.
Industries that specify Pin-in-Torx Security Screws
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Retail & display
Shopfitting and equipment exposed to the public.
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Utilities & street furniture
Cabinets, covers and enclosures outdoors.
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Correctional & secure facilities
Fixings that must resist tampering with ordinary tools.
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Public buildings & transport
Signage, panels and washroom fittings in unsupervised places.
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Food, pharma & cleanroom
Stainless assemblies that are washed down, where the finish matters as much as the strength.
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Machine building & OEM
The default fastener on production equipment: covers, brackets, motor mounts and sub-assemblies tightened to a specified torque.
Typical applications
- pin-in-hex and pin-in-Torx where authorised service still needs access
- fixings meant to resist casual removal
- one-way heads where the fixing should never come out
- bolting brackets, motors and gearboxes to a frame
- assemblies that are dismantled for service and re-torqued
- joints where the property class is stated on the drawing
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
- 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 Pin-in-Torx Security Screws are used, how to specify them, and the cases they are wrong for
