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Steel 35W250 vs M15

Steel · grade comparison

Steel 35W250 and M15 are both steel grades. 35W250 is the stronger of the two: yield strength 360 MPa (52.2 ksi) against 340 MPa (49.3 ksi) for M15, about 6% more. In exchange, M15 is the more ductile: elongation 15% versus 12% for 35W250, and 35W250 is harder (180 HB vs 165 HB). M15 runs hotter in service (200°C vs 180°C continuous). On the shop floor, M15 welds better (50 vs 35 out of 100) and M15 sits in a lower cost tier (budget, $) than 35W250 (standard, $$).

35W250Choose it when strength drives the design.

M15Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

35W250 vs M15: properties

35W250M15

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

195 GPa28.3 Msi
200 GPa29 Msi

Shear Modulus

76 GPa11 Msi
78 GPa11.3 Msi

Poisson's Ratio

0.3
0.29

Tensile Strength (Ultimate)

480 MPa69.6 ksi
470 MPa68.2 ksi

Yield Strength (0.2% offset)

360 MPa52.2 ksi
340 MPa49.3 ksi

Elongation at Break

12%
15%

Compressive Strength

360 MPa52.2 ksi
—

Fatigue Strength (Endurance Limit)

210 MPa30.5 ksi
220 MPa31.9 ksi

Charpy V-Notch Impact (RT)

5 J3.7 ft·lbf
—

Hardness, Brinell

180 HB
165 HB

Hardness, Vickers

190 HV
175 HV

Same in both: Bulk Modulus 160 GPa23.2 Msi · Shear Strength 330 MPa47.9 ksi · Hardness, Rockwell B 82 HRB

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,490°C2,714 °F
1,500°C2,732 °F

Liquidus Temperature

1,510°C2,750 °F
1,520°C2,768 °F

Same in both: Density 7.65 g/cm³0.28 lb/in³

Thermal

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

Thermal Conductivity

24 W/m·K13.9 BTU/hr·ft·°F
22 W/m·K12.7 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

11.5 µm/m·K6.4 µin/in·°F
12 µm/m·K6.7 µin/in·°F

Latent Heat of Fusion

260 J/g112 BTU/lb
250 J/g107 BTU/lb

Max Service Temperature (continuous)

180°C356 °F
200°C392 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Min Service Temperature -60°C-76 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

3.1 % IACS
3.4 % IACS

Electrical Resistivity

5.5×10⁻⁷ Ω·m21.7 µΩ·in
5×10⁻⁷ Ω·m19.7 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

18 / 100
15 / 100

Galvanic Potential (seawater, vs SCE)

—
-0.6 V

Manufacturability

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

Machinability Rating (AISI 1212 = 100 %)

45%
55%

Weldability

35 / 100
50 / 100

Formability (cold)

45 / 100
55 / 100

Brazeability / Solderability

30 / 100
45 / 100

Polishability

40 / 100
50 / 100

Same in both: Machinability 45 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

32 MJ/kg13,758 BTU/lb
34 MJ/kg14,617 BTU/lb

Embodied Water

45 L/kg5.4 gal/lb
60 L/kg7.2 gal/lb

Typical Recycled Content

15%
25%

Same in both: Embodied Carbon (primary production) 2.4 kg CO₂/kg

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

63 kN·m/kg
61 kN·m/kg

Specific Stiffness (E / density)

25.5 MN·m/kg
26.1 MN·m/kg

Modulus of Resilience

332 kJ/m³
289 kJ/m³

Thermal Diffusivity

6.7 mm²/s
6.1 mm²/s

Thermal Shock Resistance Index

5
4

Strength versus weight

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

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scale35W250M15

Manufacturing and finishing

Capability35W250M15
Sheet metalYes—
Default conditionFinal Annealed—
Relative cost$$ Standard$ Budget
Min. machined wall——
Best machined surface——
Black OxideYes—
CerakoteYes—
Chrome PlatingYes—
E-CoatingYes—
Hot-Dip GalvanizingYes—
Nickel PlatingYes—
PTFE CoatingYes—
PaintingYes—
Powder CoatingYes—
Tin PlatingYes—
Zinc PlatingYes—
Zinc-Flake (Dip-Spin) CoatingYes—
Zinc-Nickel PlatingYes—

They share 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

35W250 vs M15 — frequently asked

Is 35W250 stronger than M15?

Yes. 35W250 has a typical yield strength of 360 MPa (52.2 ksi) against 340 MPa (49.3 ksi) for M15 — about 6% more. Tensile strength is 480 MPa (69.6 ksi) vs 470 MPa (68.2 ksi).

Which is cheaper, 35W250 or M15?

M15 is the lower-cost material: it sits in the budget tier ($) while 35W250 is standard ($$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which welds better, 35W250 or M15?

M15. Its weldability rates fair (50/100) against fair (35/100) for 35W250.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 35W250 and M15 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.