HexFastener Resources

Engineering Guides

Practical references for buyers and engineers sourcing industrial fasteners — threads, property classes, materials and coatings, written from production experience.

grade · high strength

Grade 8.8 vs 10.9 vs 12.9: What Metric Property Classes Actually Tell You

The two numbers in a metric property class encode tensile strength and yield ratio. How to read them, how they map to SAE/ASTM grades, and when paying for 12.9 is justified.

Aug 19, 2026 2 min read