Material datasheet · Low-alloy steel
AISI 4130 Cr-Mo Alloy Steel
UNS G41300 · Normalized or annealed; commonly TIG/MIG welded as tubing
The weldable Cr-Mo alloy steel. Aircraft tubing standard.
Chemical composition
Nominal % by weight.
| Element | % by wt |
|---|---|
| Fe | Bal. |
| C | 0.28–0.33 |
| Cr | 0.80–1.10 |
| Mo | 0.15–0.25 |
Applicable specifications
AMS / ASTM / MIL.
- AMS 6345
- AMS 6360 (tube)
- AMS 6373
- MIL-T-6736
Machining guidance
CNC parameters and tooling.
Carbide; standard geometry
The weldable Cr-Mo. Holds up well after weld + stress relief. Lower hardenability than 4140.
Stock & cost
Forms and Q1 2026 pricing.
- Powder coat
- Paint (zinc primer)
- Phosphate
- Black oxide
Typical applications
Where 4130 Chromoly is the right pick.
- Aircraft tubular structure
- Race car frames
- Firearms barrels
- Bicycle frames
- Roll cages
Alternative materials
Substitute or upgrade options.
- 4140 (higher strength, lower weldability)
- 1020 mild steel (cheaper, lower strength)
Digital Machine · Quick-Turn CNC · California
Machine your part in 4130 Chromoly.
Production CNC milling and turning. Confirm material, inspection and documentation requirements when requesting a quote.
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Related tools & references
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SFM, RPM, and feed rate for this material.
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Estimate part weight from 4130 Chromoly stock.
Aerospace specs that call out this alloy.