What Is the Difference Between AMS 4928 and AMS 4928W?
AMS 4928W is the current revision of the AMS 4928 specification for Ti-6Al-4V bars and forgings; the letter identifies which issue of the same specification is required.
Published: Move Metal
AMS 4928 is the SAE aerospace material specification covering bars, wire, forgings and rings of the Ti-6Al-4V (Grade 5) titanium alloy in the annealed condition. The trailing letter (e.g. AMS 4928W) identifies the revision: each revision is an updated issue of the same numbered specification.
What does the letter tell you?
SAE AMS specifications are reviewed over time; referenced test methods, acceptance criteria, documentation and definitions are updated. Revision letters advance alphabetically; W follows the earlier issues (V, U, T…). For purchasing this means: if the customer specifies “AMS 4928W”, the supplier must provide material produced and certified to exactly that revision; “AMS 4928, latest revision” points to the most recent issue at the date of order.
Why does it matter?
- The revision stated on the mill test certificate (MTC) must match the customer specification exactly; a mismatch creates a non-conformance at incoming inspection.
- Aerospace and defense customers usually specify a particular revision or “latest revision” in their requirements.
- Stock material produced to an earlier revision may require additional testing or re-certification when a newer revision is requested.
Do not confuse with similar specifications
- AMS 4965: Separate specification for the same alloy in the solution treated and aged (STA) condition; mechanical properties differ.
- AMS 4911: Ti-6Al-4V sheet, strip and plate.
- ASTM B348 Grade 5: ASTM specification for industrial use; not considered equivalent to aerospace AMS requirements.
Materials with the same chemistry differ between these specifications in heat treatment, testing and certification. Equivalency is not automatic; it must be confirmed against the applicable specification.
What to state in your request
Specification and revision (e.g. AMS 4928W), form and dimensions, cut length, quantity, required condition, additional requirements such as ultrasonic inspection (e.g. AMS 2631), certificate type and origin requirements. Complete information makes supplier confirmation and quotation much faster.