It's the tensile strength of the bolt/nut. 12.9grade don't tend to bend, only snap when under very high stresses.
Standard off the shelf steel bolt will be 8.8, if it has no markings expect it to be poor quality. Stainless steel bolts are around 5.7 iirc
@O'Shane started
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It's the tensile strength of the bolt/nut. 12.9grade don't tend to bend, only snap when under very high stresses.
Standard off the shelf steel bolt will be 8.8, if it has no markings expect it to be poor quality. Stainless steel bolts are around 5.7 iirc