Specifications
Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175/ISO 15156-2
- NORSOK M-650
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
AMS 5731 — A286 Bar, Forging, Tubing and Rings Solution-Treated
AMS 5731 is the SAE Aerospace Material Specification covering A286 (UNS S66286) bar, forging, tubing, and rings in solution-treated condition at 1800 °F (982 °C). Used as raw stock when downstream aging is performed by the customer (typically after machining to final dimension). AMS 5731 is the canonical sol-treated A286 bar spec — the chemistry is identical to AMS 5732 / 5737 but the heat-treatment is sol-treatment-only, leaving aging for the downstream user. Distinguished from AMS 5732 (sol + aged from mill) and AMS 5737 (precision sol + aged) by aging condition. See parent A286 AMS specifications hub, related A286 round bar, forged bar, and the canonical A286 chemical composition.
Spec Scope & Coverage
AMS 5731 covers A286 bar, forging, tubing, and rings in solution-treated condition. Material is VIM-VAR melted, hot-worked to the required form, solution-treated 1800 °F (982 °C) per the spec, oil-quenched. Bar tolerance per AMS 5731 dimensional table; forgings per drawing. Hardness 24-28 HRC after sol-treatment. Customer performs aging (typically 1325 °F × 16 hours) after machining to final dimension. Used as raw stock for downstream cold-heading, machining, and forging operations.
A286 Chemical Composition (UNS S66286)
| Element | Min % | Max % | Notes |
|---|---|---|---|
| Iron (Fe) | Balance | Balance | ~53 % typical |
| Nickel (Ni) | 24.0 | 27.0 | Solid-solution stabilizer |
| Chromium (Cr) | 13.5 | 16.0 | Corrosion + oxidation resistance |
| Titanium (Ti) | 1.90 | 2.35 | Gamma-prime former (Ni3Ti) |
| Molybdenum (Mo) | 1.00 | 1.50 | Solid-solution strengthener |
| Vanadium (V) | 0.10 | 0.50 | Carbide stabilizer |
| Aluminium (Al) | 0 | 0.35 | Gamma-prime former (Ni3Al) |
| Boron (B) | 0.001 | 0.010 | Grain-boundary strengthening |
| Carbon (C) | 0 | 0.08 | Per ASTM A453 |
| Manganese (Mn) | 0 | 2.00 | Per ASTM A453 |
| Silicon (Si) | 0 | 1.00 | Per ASTM A453 |
| Phosphorus (P) | 0 | 0.025 | Trace impurity |
| Sulphur (S) | 0 | 0.015 | Trace impurity |
AMS 5731 — A286 Bar, Forging, Tubing and Rings Solution-Treated — Spec Requirements
| Property | AMS 5731 requirement | Notes |
|---|---|---|
| Form | Bar, forging, tubing, rings | Wide form coverage |
| Heat treatment | Solution-treated 1800 °F (982 °C) | Aging done downstream by customer |
| Tensile strength (sol-treated) | Per spec — typically 670 MPa | Customer ages to develop full strength |
| Yield strength (sol-treated) | Per spec — typically 380 MPa | Customer ages to develop full yield |
| Hardness (sol-treated) | 24-28 HRC | Soft for machinability |
| Hardness (post-aging by customer) | 29-32 HRC | Customer measures after aging |
| Surface finish | Pickled | No mill scale |
| Magnetic permeability | < 1.005 | Per ASTM A342 |
When to Specify AMS 5731 — A286 Bar, Forging, Tubing and Rings Solution-Treated
- Cold-heading / fastener manufacture: AMS 5731 sol-treated bar feeds cold-heading into hex bolts, SHCS, hex nuts with downstream aging.
- Machining sol-treated for ease: AMS 5731 soft sol-treated condition is easier to machine than aged AMS 5732 — for complex machined parts, machine in sol-treated state then age.
- Forging blanks: AMS 5731 bar / forging blanks for downstream closed-die forging into A286 forgings, A286 flanges.
- Pre-aged bar alternative: For aged bar ready for use, specify AMS 5732 or AMS 5737 instead.
- Industrial bar substitute: ASTM B637 covers similar sol-treated bar for non-aerospace industrial applications.
AMS 5731 — A286 Bar, Forging, Tubing and Rings Solution-Treated — Frequently Asked Questions
What is AMS 5731?
SAE / AMS spec covering A286 (UNS S66286) bar, forging, tubing, and rings in solution-treated condition (1800 °F sol). Customer performs aging downstream — typically after machining to final dimension.
AMS 5731 vs AMS 5732 — which to specify?
AMS 5731: sol-treated only, customer ages downstream. AMS 5732: sol-treated AND aged from mill, ready for use. Choose AMS 5731 when aging timing is critical to dimensional stability (e.g., precision machined parts where aging after final geometry); AMS 5732 for direct use without further heat treatment.
Is AMS 5731 cheaper than AMS 5732?
Slightly — AMS 5731 omits the aging step at the mill, saving 16 hours of furnace time and electricity. Typical 5-10 % cost savings vs AMS 5732. Customer must perform aging downstream, adding back the cost on the customer side.
What's the heat-treatment temperature for AMS 5731?
Solution-treatment 1800 °F (982 °C) for 1 hour per inch of section, oil-quench. NO aging performed at the mill — aging is done downstream at 1325 °F (718 °C) for 16 hours.
Can AMS 5731 bar be used directly without aging?
NO — sol-treated condition has only ~380 MPa yield (vs 655 MPa aged). Must be aged downstream to develop full A286 mechanical properties (130 ksi tensile / 95 ksi yield). For direct use, specify AMS 5732.
Is AMS 5731 the same as ASTM B637?
Different aerospace vs industrial scope. Chemistry is identical (UNS S66286). AMS 5731 has aerospace AS9100D AQMS implications; ASTM B637 is industrial. For ASME pressure-vessel applications, ASTM B637 is more commonly cited.
What's the lead time on AMS 5731 bar?
Standard sizes 5-50 mm: 4-6 weeks from heat release (no aging step). Larger sizes 50-200 mm: 6-10 weeks. Customer downstream aging adds 1-3 days plus cool-down.
Is AMS 5731 magnetic?
No. Magnetic permeability < 1.005 verified per ASTM A342. Compatible with non-magnetic instrumentation, MRI, and aerospace electromagnetic-sensitive applications.
Can AMS 5731 be NACE MR0175 compliant?
Yes — when supplied with hardness ≤ HRC 35 (HV ≤ 327) per NACE MR0175 / ISO 15156-3 for sour-service. The sol-treated condition is below this hardness; downstream aging may push hardness above HRC 35 — verify after aging.
Mechanical Properties per This Spec
| Property | Min value (sol-treated) | After customer aging |
|---|---|---|
| Tensile strength (MPa) | ≥ 670 | ≥ 895 |
| Yield strength 0.2 % (MPa) | ≥ 380 | ≥ 585 |
| Hardness HRC | 24-28 | 29-32 |
A286 Products Manufactured per This Spec
TorqBolt manufactures the following A286 products to this specification:
- A286 Round Bar
- A286 Hex Bar
- A286 Forged Bar
- A286 Hollow Bar
- A286 Forgings (raw stock)
- A286 Welding Rod (sol-treated stock)
Mating & Related Specifications
Common mating and related A286 specifications used alongside this spec:
- AMS 5732 — Mill-aged variant — ready for use without downstream aging.
- AMS 5737 — Precision-aged bar variant.
- ASTM B637 — Industrial alternative for non-aerospace applications.
Drawing Call-Out Example
A286 round bar, AMS 5731, sol-treated, ⌀ 25.4 mm × 3000 mm length, hot-rolled pickled finish, ±0.10 mm OD tolerance, EN 10204 3.1.
Related A286 Specifications & Reference
Other A286 specifications: AMS / ASTM hub · AMS 5525 · AMS 5731 · AMS 5732 · AMS 5737 · AMS 5853 · AMS 5895 · ASTM A453 grade 660 · ASTM A638 grade 660 · ASTM B637 · DIN 1.4980 · UNS S66286.
Canonical A286 reference: A286 chemical composition · A286 mechanical properties · A286 heat treatment · alloy comparisons (vs Inconel 718 · vs Waspaloy).
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