Material page for bicycle general threaded fasteners in A4 Stainless Steel (ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80). The sizes below are the ones we supply; there is no published dimensional standard for this article, so the table rather than a standard number is what to quote. Corrosion behaviour is superior, including marine and chloride environments and the service range is approx. -200 °C to +400 °C, subject to the property class and the joint.
Why Choose A4 Stainless Steel for Bicycle General Threaded Fasteners
Specified for marine, coastal and chemical applications. For bicycle general threaded fasteners, this matters when superior, including marine and chloride environments is the primary requirement.
Mechanical & Physical Properties
| Grade designation | ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80 |
|---|---|
| Magnetic response | Largely non-magnetic |
| Service temperature | approx. -200 °C to +400 °C, subject to the property class and the joint |
| Corrosion characteristic | Superior, including marine and chloride environments |
Corrosion Behavior in Service
A4 (316) adds 2–3% molybdenum to the A2 (304) composition, which dramatically improves resistance to chloride-pitting corrosion. For Bicycle General Threaded Fasteners in marine, coastal, swimming-pool or food-processing environments, A4 is the default selection.
Comparable Grades
For Bicycle General Threaded Fasteners, the alternative stainless grade is A2 (304). Choose A2 (304) for general use and A4 (316) wherever chlorides are present; the molybdenum in A4 is the whole difference. Remember that stainless is the corrosion answer, not the strength answer — for load, look at class 8.8 or 10.9 instead.
Using Stainless Fasteners in Aluminum
Expect the aluminum to corrode, not the fastener — stainless sits higher in the galvanic series, so the aluminum is the one that gives up material. A small fastener in a thick section spreads the loss over a large area and is usually fine; a large fastener in thin sheet concentrates it and is not. Keep water out of the joint, or isolate the two metals with a nylon or coated washer and a sealant.
Sizes of Bicycle General Threaded Fasteners Available in A4 Stainless Steel
| Thread designation | Pitch | Typical bicycle location |
|---|---|---|
| M3 | 0.5 | dropout adjustment and small accessory hardware |
| M4 | 0.7 | some derailleur limit screws |
| M4 | 0.75 | common JIS derailleur limit screws |
| M5 | 0.8 | pinch bolts, rotor, fender, rack and bottle-cage mounts |
| M6 | 1.0 | brake caliper, brake pad and rack/fender hardware |
| M7 | 1.0 | some handlebar binder bolts |
| M8 | 0.75 | chainring bolts |
| M8 | 1.25 | stem, crank and suspension hardware |
| 2.2 mm spoke | 56 TPI | common 2 mm spoke threading |
Dimensions are independent of the material: every size above is available in A4 Stainless Steel.
Custom manufacturing · Made to drawing
Need this screw in a grade that is not listed?
A4 Stainless Steel is one of the grades the catalog describes. Material and finish are usually what drives a special — a grade the standard part is not stocked in, or a coating chosen against a salt-spray figure instead of a default. Made by cold heading or warm forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
