Stainless Steel XM-9-A (Solution annealed)
Temper
UNS S36200
Pick for stock bar/wire that will be machined, cold-headed or formed before the customer's own ageing treatment.
Values for the A condition
Other XM-9 tempers and conditions
XM-9 is listed in 8 conditions; see the grade overview at XM-9.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AThis page Solution annealed | Pick for stock bar/wire that will be machined, cold-headed or formed before the customer's own ageing treatment. | 690 | 900 | 18 | 30 HRC | 2.2 % IACS |
Overaged 621 °C (1150 °F) for 4 h, maximum toughness | Pick as the most ductile, toughest and most SCC-tolerant aged condition, e.g. for sour or marine-adjacent service. | 795 | 930 | 18 | 30 HRC | — |
Condition A, cold drawn | Pick for cold-heading wire and straight, close-tolerance bar where a modest strength increase over Condition A is useful before ageing. | 860 | 1,000 | 13 | 33 HRC | — |
Aged 593 °C (1100 °F) for 4 h | Pick for over-aged parts needing good toughness and dimensional stability at moderate strength. | 930 | 1,000 | 16 | 33 HRC | — |
Solution treated and aged ~565 °C | Pick where improved toughness and chloride SCC resistance matter more than peak strength. | 1,000 | 1,070 | 15 | 35 HRC | — |
Solution treated and aged ~540 °C | Pick as the general-purpose balance of strength, ductility and stress-corrosion resistance. | 1,070 | 1,170 | 14 | 38 HRC | — |
Solution treated and aged ~510 °C | Pick when near-peak strength is wanted with slightly better ductility and toughness than H900. | 1,170 | 1,275 | 13 | 41 HRC | — |
H900Default Aged 482 °C (900 °F) for 1 h, peak hardness | Pick for maximum strength and hardness in fasteners and highly loaded fittings where notch toughness and chloride exposure are controlled. | 1,240 | 1,345 | 12 | 43 HRC | — |
What is XM-9-A?
XM-9-A is XM-9 in the A temper — pick for stock bar/wire that will be machined, cold-headed or formed before the customer's own ageing treatment. XM-9-A has a yield strength of 690 MPa (100 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 92% of stainless steel grades. Elongation at break is 18% and the elastic modulus is 200 GPa (29 Msi). XM-9-A has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,400°C (2,552 °F). H900 is the default condition FabDigit quotes; A is available on request or by drawing note.
Advantages
- High strength — 690 MPa (100 ksi), better than 92% of stainless steel grades
Limitations
- Limited ductility — 18%, worse than 83% of stainless steel grades
- Limited service temperature — 400°C (752 °F), worse than 78% of stainless steel grades
XM-9-A properties
Typical room-temperature values for XM-9-A; 21 are specific to this condition. Other listed values are XM-9 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
XM-9-A has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical16
XM-9-A has a yield strength of 690 MPa (100 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 92% of stainless steel grades. Elongation at break is 18% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
XM-9-A is rated for continuous service to 400°C (752 °F). It conducts heat at 15.8 W/m·K (9.13 BTU/hr·ft·°F), better than 55% of stainless steel grades. Thermal expansion is 10.8 µm/m·K (6 µin/in·°F).
Electrical3
XM-9-A conducts electricity at 2.2 % IACS, worse than 72% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (60/100), worse than 58% of stainless steel grades.
Sustainability4
Producing a kilogram of XM-9-A takes about 55 MJ of energy and emits 4.7 kg of CO₂ — more than 50% of stainless steel grades. Typical recycled content is 45%.
Manufacturability7
XM-9-A's machinability is fair (40/100, better than 72% of stainless steel grades); weldability good (65/100); formability fair (48/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with XM-9-A
Is XM-9 easy to machine?
Machine in Condition A with sharp, rigid, positive-rake carbide tooling, heavy feeds and flood coolant; finish-machine oversize if ageing follows, since H900 at ~43 HRC roughly halves tool life.
Can XM-9 be welded?
GTAW/GMAW/EBW with matching or 17-4 PH filler and low heat input; re-solution treat and re-age after welding to restore full properties, and avoid welding parts already in the aged condition.
Can XM-9 be formed, bent or molded?
Cold form, bend and cold-head only in the annealed condition with generous radii and interstage stress relief; all significant forming must precede the ageing cycle.
What surface finishes work on XM-9?
Passivate per ASTM A967 (nitric or citric) after machining; electropolishing and fine mechanical polishing give a bright, durable surface — no anodizing; bake after any plating to avoid hydrogen embrittlement at H900 strength.
XM-9 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Clow carbon for soft martensite | ≤ 0.05 | 0.03 |
| Mn | ≤ 0.5 | 0.3 |
| Si | ≤ 0.5 | 0.3 |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Crpassivity | 14 – 14.5 | 14.25 |
| Nicontrols Ms and martensite formation | 6.25 – 6.75 | 6.5 |
| TiNi3Ti precipitation strengthener | 0.65 – 0.9 | 0.8 |
| Fe | balance | — |
XM-9-A — frequently asked
What is XM-9-A used for?
XM-9-A is typically used for aerospace fasteners, structural hardware and fittings, cold-headed bolts and screws, pins and clevises, threaded rod ends and machined brackets and lugs. In short: aerospace fastener PH grade; high strength at 43 HRC; age-hardened after forming.
What is the yield strength of XM-9-A?
XM-9-A has a typical yield strength of 690 MPa (100 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 92% of stainless steel grades. Strength varies by condition: see the 8 listed tempers.
Is XM-9-A easy to machine?
Not especially — machinability is rated fair (40/100, better than 72% of stainless steel grades). Machine in Condition A with sharp, rigid, positive-rake carbide tooling, heavy feeds and flood coolant; finish-machine oversize if ageing follows, since H900 at ~43 HRC roughly halves tool life.
Can XM-9-A be welded?
Yes — weldability is rated good (65/100). GTAW/GMAW/EBW with matching or 17-4 PH filler and low heat input; re-solution treat and re-age after welding to restore full properties, and avoid welding parts already in the aged condition.
What surface finishes work on XM-9-A?
Passivate per ASTM A967 (nitric or citric) after machining; electropolishing and fine mechanical polishing give a bright, durable surface — no anodizing; bake after any plating to avoid hydrogen embrittlement at H900 strength.
Can XM-9-A be formed, bent or molded?
Cold form, bend and cold-head only in the annealed condition with generous radii and interstage stress relief; all significant forming must precede the ageing cycle.
What is the maximum service temperature of XM-9-A?
XM-9-A is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between XM-9-H900 and XM-9-A?
H900 is the default condition — pick for maximum strength and hardness in fasteners and highly loaded fittings where notch toughness and chloride exposure are controlled. A: pick for stock bar/wire that will be machined, cold-headed or formed before the customer's own ageing treatment. Yield strength is 1,240 MPa in H900 versus 690 MPa in A.
Sources
- ASTM A564/A564M — Hot-Rolled and Cold-Finished Age-Hardening Stainless Steel Bars and Shapes — ASTM International (2019)
- ASTM A484/A484M — General Requirements for Stainless Steel Bars, Billets and Forgings — ASTM International (2020)
- SAE J1086 / UNS Metals & Alloys Numbering System — SAE International / ASTM (2017)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Specialty Handbook — Stainless Steels — ASM International (1994)
- Precipitation-hardening stainless bar product data (Almar 362 / S36200 class) — specialty stainless producers (2020)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.