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Stainless Steel XM-15 1/4H vs XM-15 3/4H

Stainless Steel · XM-15 temper comparison

XM-15 1/4H and XM-15 3/4H are two conditions of the same stainless steel grade, XM-15: 1/4H (quarter hard) versus 3/4H (three-quarter hard). The chemistry is identical, so every difference below comes from the condition. XM-15 3/4H is the stronger of the two: yield strength 830 MPa (120 ksi) against 520 MPa (75.4 ksi) for XM-15 1/4H, about 60% more; tensile strength follows at 1,010 MPa (146 ksi) vs 760 MPa (110 ksi). In exchange, XM-15 1/4H is the more ductile: elongation 25% versus 10% for XM-15 3/4H, and XM-15 3/4H is harder (310 HB vs 240 HB). XM-15 1/4H runs hotter in service (425°C vs 370°C continuous). On the shop floor, XM-15 1/4H welds better (very good vs good).

XM-15 1/4HChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

XM-15 3/4HChoose it when strength drives the design.

XM-15 1/4H vs XM-15 3/4H: properties

XM-15 1/4HXM-15 3/4H

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

760 MPa110 ksi
1,010 MPa146 ksi

Yield Strength (0.2% offset)

520 MPa75.4 ksi
830 MPa120 ksi

Elongation at Break

25%
10%

Reduction in Area

45%
25%

Shear Strength

480 MPa69.6 ksi
620 MPa89.9 ksi

Fatigue Strength (Endurance Limit)

320 MPa46.4 ksi
420 MPa60.9 ksi

Charpy V-Notch Impact (RT)

85 J62.7 ft·lbf
40 J29.5 ft·lbf

Hardness, Brinell

240 HB
310 HB

Hardness, Rockwell B

100 HRB
82 HRB

Hardness, Vickers

250 HV
320 HV

Same in both: Elastic (Young's) Modulus 196 GPa28.4 Msi · Shear Modulus 77 GPa11.2 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,370°C2,498 °F · Liquidus Temperature 1,400°C2,552 °F

Thermal

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

Max Service Temperature (continuous)

425°C797 °F
370°C698 °F

Same in both: Thermal Conductivity 14.5 W/m·K8.4 BTU/hr·ft·°F · Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 16.5 µm/m·K9.2 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

8.5×10⁻⁷ Ω·m33.5 µΩ·in
8.6×10⁻⁷ Ω·m33.9 µΩ·in

Same in both: Electrical Conductivity 2 % IACS

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

64 / 100
60 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.07 V

Manufacturability

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

Machinability

42 / 100
34 / 100

Machinability Rating (AISI 1212 = 100 %)

45%
37%

Weldability

75 / 100
65 / 100

Formability (cold)

50 / 100
25 / 100

Same in both: Castability 45 / 100 · Brazeability / Solderability 65 / 100 · Polishability 80 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 58 MJ/kg24,936 BTU/lb · Embodied Carbon (primary production) 5.6 kg CO₂/kg · Embodied Water 130 L/kg15.6 gal/lb · Typical Recycled Content 55%

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-15

XM-15 1/4H vs XM-15 3/4H — frequently asked

Is XM-15 3/4H stronger than XM-15 1/4H?

Yes. XM-15 3/4H has a typical yield strength of 830 MPa (120 ksi) against 520 MPa (75.4 ksi) for XM-15 1/4H — about 60% more. Tensile strength is 1,010 MPa (146 ksi) vs 760 MPa (110 ksi).

Which condition does FabDigit quote by default, 1/4H or 3/4H?

Annealed is the default XM-15 condition in the FabDigit quote flow (neither 1/4H nor 3/4H). 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-15 1/4H or XM-15 3/4H?

XM-15 1/4H. Its machinability rates fair (42/100) against poor (34/100) for XM-15 3/4H; for welding the order is XM-15 1/4H first (very good, 75/100) then XM-15 3/4H (good, 65/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in XM-15 1/4H and XM-15 3/4H 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.