AMS 4928 Grade 5 Titanium Bar — Ti-6Al-4V (R56400) Aerospace Bar from Baoji

Опубликовано Engineering Team, Shaanxi Qianyi Tuoda Technology Co., Ltd от 2026-11-04

Titanium Grade 5 bar · AMS 4928 · Ti-6Al-4V · UNS R56400

AMS 4928 is the SAE aerospace specification for Ti-6Al-4V (Grade 5, UNS R56400) bar — double vacuum-arc remelted, fracture-toughness controlled and fully traceable to the melt. Where an aerospace or defence drawing calls out AMS 4928, a commercial ASTM B348 bar will not pass. SXQYTD supplies AMS 4928 Grade 5 bar with double-VAR melt certification, UT to AMS 2631 and a 3.1 / 3.2 material certificate. Below is the detail that decides form, condition and inspection before you issue a PO.

Material	Grade 5 (UNS R56400, Ti-6Al-4V)	Principle	Double-VAR aerospace bar
Type & stock	Round / square / hex / forged bar	Industry	Aerospace, defence, high-end medical
Standard	AMS 4928 (SAE) · annealed	Lead time	1–2 weeks stock; 3–5 weeks custom

1. What an AMS 4928 bar is — by grade and by form

By grade, it is Ti-6Al-4V (Grade 5, UNS R56400) — the alpha-beta alloy that carries most airframe and engine loads. By specification, AMS 4928 is the SAE aerospace issue of that bar (annealed), covering round, square, hexagon, flat and forged bar plus wire, forgings and rings. It is the document an aerospace drawing references; ASTM B348 is the commercial/industrial equivalent and is not a substitute where AMS 4928 is mandated. (STA condition, when needed, is covered by AMS 4965.) By form, we stock round bar from Ø6 mm up to large section, plus square, hex and forged billet for subsequent forging.

2. Why AMS 4928 — not just any Grade 5 bar

The metal chemistry looks the same as B348, but the controls around it are what an aerospace buyer pays for. Match the spec to the duty:

Duty	Spec to specify	Why
Aerospace drawing	AMS 4928	Double-VAR, fracture toughness, UT Class A.
Commercial / industrial	ASTM B348 Gr5	Same alloy, lighter documentation.
High strength STA	AMS 4965	Solution-treated and aged.
Implant	ASTM F136 (ELI)	Lower interstitials, biocompatible.

Three things an AMS 4928 buyer must verify: (1) the bar must come from a double vacuum-arc remelted (VAR) ingot — single-melt or EB/hearth-melt stock is rejected on melt records; (2) ultrasonic acceptance is to AMS 2631 Class A (tighter than commercial UT), so a "clean" B348 bar can still fail; and (3) the certificate must trace to the heat and melt source — a generic 3.1 without melt practice will not clear first-article review.

3. Technical standards we build to

• Spec: AMS 4928 (SAE), Ti-6Al-4V, annealed; certificate EN 10204 3.1 (3.2 on request).
• Melt practice: double vacuum-arc remelted (VAR), melt-source documented.
• Chemistry (R56400, AMS): Al 5.50–6.75 %, V 3.50–4.50 %, Fe ≤ 0.25 %, O ≤ 0.20 %, C ≤ 0.08 %, N ≤ 0.05 %, H ≤ 0.015 %, Y ≤ 0.005 %.
• Mechanical (annealed): tensile 895–930 MPa (130–135 ksi), yield ≥ 828 MPa (120 ksi), elongation ≥ 10 %, reduction of area ≥ 25 %.
• Inspection: UT to AMS 2631 Class A, PT to AMS 2644, chemistry & grain per spec.

4. Manufacturing flow — from double-VAR ingot to your bar

1) Double-VAR ingot with melt certificate → 2) Forge / roll to bar → 3) Anneal per AMS 4928 → 4) Pickling / passivation (remove α-case) → 5) Straightening → 6) Band-saw cutting to length → 7) UT (AMS 2631 Class A) + PT (AMS 2644) → 8) Dimensional and grain check → 9) Chemistry / PMI and heat-treat record → 10) Material certificate (3.1 / 3.2) and export packing. Every heat carries a melt-and-heat-treat package so the bar clears first-article and NADCAP-style review.

5. Key performance

Item	Control value	Note
Tensile strength	895–930 MPa	130–135 ksi.
Yield strength	≥ 828 MPa	120 ksi minimum.
Elongation / RA	≥ 10 % / ≥ 25 %	Ductility margin.
Iron limit	≤ 0.25 % (AMS)	Tighter than B348 0.40 %.
Density	4.43 g/cm³	~60 % lighter than steel.

6. Application industries

Industry	Part	Why AMS 4928
Aerospace airframe	Fittings, spars, brackets	Traceability + toughness.
Aero engine	Shafts, discs, blades	Double-VAR cleanliness.
Defence	Structural members	Melt + UT acceptance.
High-end medical	ELI Grade 23 on request	Clean, documented stock.

7. Selection guide

By spec: drawing says AMS 4928 → take this bar; says B348 → the commercial Grade 5 bar is enough and cheaper; says AMS 4965 → STA condition. By form: round for shafts and blanks, square / hex for wrench and fastener stock, forged bar for your own forgings. By certificate: ask for 3.2 (with a named surveyor / third party) if your QA requires it, otherwise 3.1 clears most first-article reviews. Send the drawing note, size, length, condition and cert level; we confirm in one reply.

8. Customizable items & accessories

• Form and size (Ø6 mm to large section; square / hex / forged bar to order).
• Condition: annealed (AMS 4928) or STA (AMS 4965) on request.
• Length: random mill length or cut to your dimension.
• Surface: peeled, ground, polished; rough-turned to save machining.
• Certificate: EN 10204 3.1 or 3.2; PMI, UT (AMS 2631 A) and PT reports.

9. Lead time, test reports & warranty

Item	Commitment
Lead time	1–2 weeks from stock; 3–5 weeks custom / large section.
Test reports	Melt cert, UT (AMS 2631 A), PT, PMI, 3.1/3.2 certificate.
Warranty	12 months against material and workmanship defects from shipment.

10. FAQ

AMS 4928 or ASTM B348 — which do I need?

If the drawing or purchase order names AMS 4928, you need this bar — the double-VAR melt, AMS 2631 Class A ultrasonic acceptance and full melt traceability are called out there, and a B348 bar will fail first-article review even though the alloy is the same. If no aerospace spec is named, ASTM B348 Grade 5 is the lower-cost, fully adequate commercial choice.

Why does double vacuum-arc remelting matter?

Titanium's fatigue and fracture behaviour are set by inclusion cleanliness and chemical homogeneity. A second VAR pass removes hard-alpha inclusions and even out the melt, lifting fracture toughness and fatigue life to the level aerospace structures require. We supply the melt certificate showing two remelts — that is the line between aerospace and commercial stock.

Annealed or solution-treated-and-aged (STA, AMS 4965)?

AMS 4928 is the annealed condition and suits most machined and forged parts with the best ductility. AMS 4965 (STA) raises strength past ~1100 MPa for high-load components but at the cost of elongation and machinability. Unless the drawing calls for STA, take annealed.