Property Class 8.8 Steel Bicycle Brake Caliper Mounting Bolts 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 Bicycle Brake Caliper Mounting Bolts are supplied to our own published dimensions — this is a trade-series article rather than one covered by a dimensional standard, so confirm the figures against the part you are replacing. 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.
Why Choose Property Class 8.8 Steel for Bicycle Brake Caliper Mounting Bolts
The workhorse medium-carbon alloy class for structural joints. For bicycle brake caliper mounting bolts, 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 bicycle brake caliper mounting bolts 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 Bicycle Brake Caliper Mounting Bolts, 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 Bicycle Brake Caliper Mounting Bolts Available in Property Class 8.8 Steel
| Thread size | Length options | Mount form | Drive / washer | Selection rule |
|---|
| M5×0.8 | 10 / 15 mm or frame-selected | flat-mount | hex socket or Torx with washer | frame/chainstay stack plus required engagement |
| M6×1.0 | application-selected | post-mount or older caliper | hex socket or Torx with washer | caliper and frame manufacturer specification |
Dimensions are independent of the material: every size above is available in Property Class 8.8 Steel.
Custom manufacturing · Made to drawing
Need this bolt in a grade that is not listed?
Grade 8 8 Steel is one of the grades the catalog describes. Where the standard stops, the drawing takes over: fine pitches, left-hand threads, partial threading, and property classes above the catalogued grade where material and heat treatment allow. Made by cold heading or hot forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
Custom bolt manufacturingSend a drawing
Applications & Industries
What Bicycle Brake Caliper Mounting Bolts are specified for, industry by industry. Stocked from M5×0.8 to M6×1.0.
Industries that specify Bicycle Brake Caliper Mounting Bolts
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Mountain bikes
Post-mount hardware uses a different mounting geometry from flat mount.
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Brake repair
Washer and drive style follow the caliper manufacturer.
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Bicycle assembly
M5 flat-mount and M6 post-mount hardware position a brake caliper.
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Bike service
Frame and chainstay thickness determine the bolt length.
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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.
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Automotive & transport
Chassis, driveline and body fixings that see vibration and are assembled to a controlled preload.
Typical applications
- calculating length from frame thickness and engagement
- using the specified drive and washer arrangement
- mounting a brake caliper to a frame boss
- selecting M5 flat-mount or M6 post-mount hardware
- 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 install a flat-mount length in a post-mount position; insufficient engagement or bottoming can damage the caliper.
- 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 Bicycle Brake Caliper Mounting Bolts are used, how to specify them, and the cases they are wrong for
