Steel M42 vs M48
Steel · grade comparison
Steel M42 and M48 are both steel grades. M48 is the stronger of the two: tensile strength 950 MPa (138 ksi) against 900 MPa (131 ksi) for M42, about 6% more. In exchange, M42 is the more ductile: elongation 12% versus 10% for M48, and M48 is harder (269 HB vs 255 HB). M48 runs hotter in service (500°C vs 400°C continuous). On the shop floor, M42 machines more easily (fair vs poor) and M48 sits in a lower cost tier (high, $$$$) than M42 (specialty, $$$$$).
M42Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
M48Choose it when strength drives the design, or when the part sees heat.
M42 vs M48: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Shear Modulus
Bulk Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Rockwell C
Hardness, Vickers
Same in both: Yield Strength (0.2% offset) 620 MPa89.9 ksi
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Same in both: Liquidus Temperature 1,420°C2,588 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Latent Heat of Fusion
Same in both: Specific Heat Capacity 420 J/kg·K0.1 BTU/lb·°F · Min Service Temperature -60°C-76 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Castability
Polishability
Same in both: Brazeability / Solderability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
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.
Manufacturing and finishing
| Capability | M42 | M48 |
|---|---|---|
| CNC machining | Yes | — |
| Default condition | Annealed | — |
| Relative cost | $$$$$ Specialty | $$$$ High |
| Min. machined wall | 0.8 mm | — |
| Best machined surface | Ra 1.6 µm | — |
| AlCrN | Yes | — |
| AlTiN | Yes | — |
| Black Oxide | Yes | — |
| CVD Al2O3 | Yes | — |
| CVD TiCN | Yes | — |
| CVD TiN | Yes | — |
| Cerakote | Yes | — |
| Chrome Plating | Yes | — |
| CrN | Yes | — |
| DLC | Yes | — |
| E-Coating | Yes | — |
| HVOF Coating | Yes | — |
| Hot-Dip Galvanizing | Yes | — |
| MoS2 | Yes | — |
| Multilayer CVD | Yes | — |
| Nickel Plating | Yes | — |
| PTFE Coating | Yes | — |
| Painting | Yes | — |
They share 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.
M42 vs M48 — frequently asked
Is M48 stronger than M42?
Yes. M48 has a typical tensile strength of 950 MPa (138 ksi) against 900 MPa (131 ksi) for M42 — about 6% more.
Which is cheaper, M42 or M48?
M48 is the lower-cost material: it sits in the high tier ($$$$) while M42 is specialty ($$$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
Which is easier to machine, M42 or M48?
M42. Its machinability rates fair (38/100) against poor (25/100) for M48; for welding the order is M42 first (poor, 20/100) then M48 (not recommended, 12/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in M42 and M48 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.