Hi Tom metric bolts are grade 8.8 10.9 12.9 imperial bolts are also grade markings for grades 5 and 8 there are other gradings of bolts but these are the main automotive ones have attached a file gradings so hopefully it works
Glen
Fasteners-Bolt-Specification-for-indication-purposes-only-based-on-upto-1_2-inch-bolt-1.jpg
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