Bicycle Brake Caliper Mounting Bolts are used primarily for mounting a bicycle brake caliper with the thread, length and mount form specified by the frame. This page lists the industries and assemblies where they are specified, the selection criteria that matter for each application, installation practice, and the cases where a different fastener type is the correct choice. Parts are supplied to Trade series (bicycle caliper mounting bolts). Stocked across roughly M5 to M6, they cover light-duty and instrument-scale work.
Typical Applications for Bicycle Brake Caliper Mounting Bolts
The most common settings where these are specified:
- Bicycle assembly: M5 flat-mount and M6 post-mount hardware position a brake caliper.
- Bike service: Frame and chainstay thickness determine the bolt length.
- Mountain bikes: Post-mount hardware uses a different mounting geometry from flat mount.
- Brake repair: Washer and drive style follow the caliper manufacturer.
How to Specify Bicycle Brake Caliper Mounting Bolts for Your Application
- Size: Match the nominal size to the mating thread or hole. This product spans M5–M6; check the full table below for the exact dimensions of each size.
- Strength class: Choose the property class (e.g. 8.8, 10.9, 12.9 or A2/A4 stainless) for the load and environment, and tighten to the matching torque so the joint relies on preload, not friction.
- Environment: For damp, coastal or chemical exposure prefer A4/316 stainless or a suitable coating; indoors, plated steel or A2 is usually sufficient.
- Standard: This is a trade-series article rather than one covered by a published dimensional standard, so dimensions can differ between manufacturers. Quote the dimensions you need — or the part you are replacing — rather than a standard number.
Installation & Assembly Practice
- Tighten to the torque for the size and property class with a calibrated wrench — the joint is held by preload, not by the thread friction alone.
- Ensure at least one full thread projects beyond the nut after tightening, and never re-use a bolt that has been tightened into yield.
- Under slotted or oversized holes, fit a hardened washer so the preload does not relax into the hole edge.
Common Selection Mistakes with Bicycle Brake Caliper Mounting Bolts
- Specifying class 12.9 "to be safe" in a corrosive environment — high classes are more sensitive to hydrogen embrittlement and stress corrosion; 8.8 hot-dip galvanized often outlasts them outdoors.
- Choosing a length that puts the shear plane through the threaded portion when a plain shank (partially threaded bolt) was available.
- Mixing stainless bolts with plated-steel nuts: the joint loses its corrosion logic and can gall or seize.
Where Bicycle Brake Caliper Mounting Bolts Are Not the Right Choice
Not for permanent joints that will never be opened (a rivet or weld is cheaper), and not where the head must sit flush — use a countersunk screw instead.
Custom manufacturing · Made to drawing
Need a bicycle brake caliper mounting bolts outside the standard range?
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 hot forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
