Fastener Materials Guide
Carbon steel, stainless, brass, and alloy bolts—when to use each and how weight and strength differ.
Common fastener materials
Choice depends on strength, corrosion resistance, and environment. Carbon steel is cheap and strong; stainless resists rust; brass is used for non-sparking or decorative use. Estimate weight with our fastener weight calculator and torque with the bolt torque calculator by material and grade.
Material comparison chart
| Material | Strength | Corrosion | Typical use |
|---|---|---|---|
| Carbon steel | High (grade-dependent) | Rusts unless coated | General, automotive |
| Stainless (304/316) | Good | Resistant | Marine, food, chemical |
| Alloy steel (Grade 8, 10.9) | Very high | Rusts unless coated | Structural, suspension |
| Brass | Lower | Good | Non-sparking, decorative |
Stainless and galling
Stainless bolts can gall (cold-weld) when similar alloys are used without lubrication. See why stainless bolts gall and use anti-seize and correct torque. Use our screw size chart and tap drill chart for sizing regardless of material.
FAQ
What is the strongest bolt material?
Alloy steel (Grade 8, 10.9, 12.9) is strongest. Stainless is strong but not top grade; brass is weaker.
When should I use stainless steel bolts?
For corrosion resistance in wet or chemical environments. Use anti-seize and correct torque to reduce galling.
Do different materials affect torque?
Yes. Torque depends on friction and strength. Use our bolt torque calculator with the correct material/grade.