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Stainless Steel XM-9-A vs XM-9-H900

Stainless Steel · XM-9 temper comparison

XM-9-A and XM-9-H900 are two conditions of the same stainless steel grade, XM-9: A (solution annealed) versus H900 (aged 482 °C (900 °F) for 1 h, peak hardness). The chemistry is identical, so every difference below comes from the condition. XM-9-H900 is the stronger of the two: yield strength 1,240 MPa (180 ksi) against 690 MPa (100 ksi) for XM-9-A, about 80% more; tensile strength follows at 1,345 MPa (195 ksi) vs 900 MPa (131 ksi). In exchange, XM-9-A is the more ductile: elongation 18% versus 12% for XM-9-H900, and XM-9-H900 is harder (400 HB vs 285 HB). XM-9-A runs hotter in service (400°C vs 315°C continuous). On the shop floor, XM-9-A machines more easily (fair vs poor) and XM-9-A welds better (good vs fair).

XM-9-AChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

XM-9-H900Choose it when strength drives the design.

XM-9-A vs XM-9-H900: properties

XM-9-AXM-9-H900

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

900 MPa131 ksi
1,345 MPa195 ksi

Yield Strength (0.2% offset)

690 MPa100 ksi
1,240 MPa180 ksi

Elongation at Break

18%
12%

Reduction in Area

58%
45%

Shear Strength

550 MPa79.8 ksi
800 MPa116 ksi

Fatigue Strength (Endurance Limit)

430 MPa62.4 ksi
620 MPa89.9 ksi

Fracture Toughness (K_IC)

110 MPa·√m100 ksi·√in
50 MPa·√m45.5 ksi·√in

Charpy V-Notch Impact (RT)

65 J47.9 ft·lbf
20 J14.8 ft·lbf

Hardness, Brinell

285 HB
400 HB

Hardness, Rockwell C

30 HRC
43 HRC

Hardness, Vickers

300 HV
425 HV

Same in both: Elastic (Young's) Modulus 200 GPa29 Msi · Shear Modulus 77 GPa11.2 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.28 · Compressive Strength 1,275 MPa185 ksi

Physical

Density and transition temperatures.

Same in both: Density 7.75 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,400°C2,552 °F · Liquidus Temperature 1,450°C2,642 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

15.8 W/m·K9.1 BTU/hr·ft·°F
16.3 W/m·K9.4 BTU/hr·ft·°F

Max Service Temperature (continuous)

400°C752 °F
315°C599 °F

Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.8 µm/m·K6 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -75°C-103 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

2.2 % IACS
2.2 % IACS

Electrical Resistivity

8×10⁻⁷ Ω·m31.5 µΩ·in
7.8×10⁻⁷ Ω·m30.7 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

60 / 100
55 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.25 V

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

40 / 100
25 / 100

Machinability Rating (AISI 1212 = 100 %)

40%
25%

Weldability

65 / 100
45 / 100

Formability (cold)

48 / 100
20 / 100

Same in both: Brazeability / Solderability 45 / 100 · Polishability 75 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 55 MJ/kg23,646 BTU/lb · Embodied Carbon (primary production) 4.7 kg CO₂/kg · Embodied Water 120 L/kg14.4 gal/lb · Typical Recycled Content 45%

Strength versus weight

Yield strength against density for every stainless steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

3005007001,0001,5002,0007.27.47.67.888.2Density (g/cm³)Yield strength (MPa) — log scaleXM-9

XM-9-A vs XM-9-H900 — frequently asked

Is XM-9-H900 stronger than XM-9-A?

Yes. XM-9-H900 has a typical yield strength of 1,240 MPa (180 ksi) against 690 MPa (100 ksi) for XM-9-A — about 80% more. Tensile strength is 1,345 MPa (195 ksi) vs 900 MPa (131 ksi).

Which condition does FabDigit quote by default, A or H900?

H900 is the default XM-9 condition in the FabDigit quote flow. The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.

Which is easier to machine, XM-9-A or XM-9-H900?

XM-9-A. Its machinability rates fair (40/100) against poor (25/100) for XM-9-H900; for welding the order is XM-9-A first (good, 65/100) then XM-9-H900 (fair, 45/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in XM-9-A and XM-9-H900 side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.

Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.