Stainless grades

Hi all, does anybody know what grade of stainless bolts are best suited to bikes? Want to upgrade my bolt supplies and replace my engine case bolts. A2 seem to cost more than A4 and the only difference I can make out is A4 or marine grade contains molybdenum.


A2 70 is the most common , fine for bikes
A4 80 has higher tensile strength and is marine grade. Also fine for bikes

Thanks John, think I’ll go for A4 then.

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Don’t use stainless bolts on exhaust or brakes

A2 is only 304 grade which will decay and lose its finish after a short amount of time A4 is 316 Stainless which is marine grade and about 10% harder than 304. 316 will be much better than 304 bearing in mind 304 and 316 aren’t much harder than mild steel.