4330 Modified / AMS 6411 Round Bar: Material Profile
4330 modified is a vanadium-bearing low-alloy steel used where strength, toughness and fatigue performance are required. The alloy is also known as 4330M or 4330V.
AMS 6411 covers premium aircraft-quality consumable-electrode-remelted material. The standard, required revision and customer additions establish the purchase requirement; a trade name alone does not.
Round bar can be reviewed as machining or forging stock against the specified condition and dimensions. Include inspection, traceability, certification and approved-source requirements with the production quantity.
Key Characteristics
- Vanadium-modified alloy
- Hardenability for high-strength components
- Toughness and fatigue performance
- Consumable-electrode-remelted material under AMS 6411
Common Applications
- Aerospace forging stock
- High-strength structural components
- Fatigue-loaded machined parts
- Production components with controlled material requirements
Ordering 4330 Modified for Production
Modified grade and revision
Include the full AMS 6411 callout and any customer specification. Retain the modified-grade designation rather than shortening the requirement to a generic 4330 request.
Condition and inspection
State the incoming bar condition, diameter, length and surface requirements. Identify required mechanical tests, inspection and heat traceability in the purchase requirement.
Production supply review
Provide total weight, first-release quantity, delivery dates and approved-source requirements. Include cutting or other processing that must be considered in the material quote.
AMS 6411: Purchasing Questions
Are 4330V, 4330M and 4330 modified equivalent purchase callouts?
They are commonly used names for vanadium-modified 4330 material, but the full specification still controls. Include AMS 6411 and all additional requirements rather than relying on the trade name alone.
Can general 4330 or 4340 be substituted?
Do not assume a substitution. A change in grade, specification or source requires the customer's approval under the applicable purchase documents.
What should accompany a larger production inquiry?
Send the required bar size and condition, quantity with units, release schedule, ship-to location and governing specifications. Include any source restrictions or certification requirements with the first inquiry.
Material References
References describe the material. Availability, source approvals and certification are confirmed for the specific order.
