Short answer: Fastener grades encode strength: metric property classes 4.8 to 12.9, SAE grades with radial marks, ASTM A325 and A490 for structural and stainless A2 or A4 for corrosion duty, all supplied from our Bolts and Nuts Supplier и Threaded Rod Supplier pages.
At a Glance
Metric Property Classes
The number before the dot is tensile strength and after is yield ratio, so 8.8 is stronger than 4.8, with examples in our Bolt Buyers Guide и Threaded Rod Guide.
SAE and ASTM
SAE grades 2, 5 and 8 use radial lines while ASTM A325 and A490 are the structural standard, with base metal in our Carbon Steel Supplier.
Stainless Grades
A2 (304) and A4 (316) stainless carry an A-plus-number mark and resist corrosion, with the choice in our Stainless Fastener Guide.
Marks and Certification
Head marks identify the class; confirm with our Quality Inspection Guide and the document detail in our Mill Test Certificate Guide.
Get a Quote
Tell HXSCO your requirements and we will respond with a competitive quote and lead time.
Часто задаваемые вопросы
Metric class: 800 MPa tensile, 0.8 yield ratio.
Grade 8 is stronger.
A490 is the higher-strength structural bolt.
A4 (316) resists marine corrosion.
They indicate it; MTC confirms.
Get a Grade-Matched Quote
HXSCO supplies fasteners in every common grade with clear head marks and MTC. Send grade, size and quantity for a quote.