Metric Bolt grade markings

Metric Bolt Grades — 12.9 vs 10.9 vs 8.8 (Plus A2-70, A4-80)

Metric Fasteners 101
Metric bolt “classes” describe minimum strength. The first number (~tensile strength/10) and the decimal (~yield ratio) tell you a lot. Example: ...
Rundown of fastener terms

Common Fastener Screw Terms explained

DIN and ISO meanings
A quick walkthrough of the easier to understand screw fastener terms and a bit longer breakdown of some of the easier to overlook, but incredibly important items like DIN and ISO usage and Metric size and pitch for the vast majority of metric screw ranges.