Short answer: Bolt selection starts with the load: class 4.8 to 8.8 for general steel, 10.9 and 12.9 for heavy duty and stainless A2 or A4 for corrosion service; match the nut and finish to the job, with supply in our Bolts and Nuts Supplier and grade detail in our Fastener Grade Guide.
At a Glance
Why Bolt Class Matters
The property class sets tensile and yield strength, so the bolt must match the joint load, with base grades in our Carbon Steel Supplier and the class system in our Fastener Grade Guide.
Carbon Steel: 4.8 to 12.9
Class 8.8 is the structural workhorse, 10.9 serves vehicles and 12.9 the highest strength, with the specification detail in our Bolts and Nuts Supplier page.
Stainless Bolts
A2 resists indoor corrosion and A4 (316) handles marine and chemical duty, with the grade choice in our Stainless Fastener Guide.
Size, Thread and Head
Pick diameter and length for clamp load, coarse or fine thread and hex or socket head, then verify each lot with our Quality Inspection Guide and keep documents per our Mill Test Certificate Guide.
Get a Quote
Tell HXSCO your requirements and we will respond with a competitive quote and lead time.
Questions fréquemment posées
Class 8.8 or A325 high-strength bolts.
Yes – roughly 50 percent higher tensile.
A4 (316) for marine and chemical use.
Use the same class or one step higher.
Yes – MTC with mechanical test.
Get a Bolt Quote
HXSCO supplies bolts in class 4.8 to 12.9 and stainless A2 / A4 with MTC. Send size, grade and quantity for a quote.