Steel 34MnB5 vs S275M
Steel · grade comparison
Steel 34MnB5 and S275M are both steel grades. 34MnB5 is the stronger of the two: yield strength 420 MPa (60.9 ksi) against 300 MPa (43.5 ksi) for S275M, about 40% more; tensile strength follows at 620 MPa (89.9 ksi) vs 440 MPa (63.8 ksi). In exchange, S275M is the more ductile: elongation 28% versus 14% for 34MnB5, and 34MnB5 is harder (185 HB vs 140 HB). 34MnB5 runs hotter in service (400°C vs 350°C continuous) and S275M conducts electricity better (9 % IACS vs 8 % IACS). On the shop floor, S275M welds better (excellent vs good) and S275M sits in a lower cost tier (budget, $) than 34MnB5 (standard, $$).
34MnB5Choose it when strength drives the design, or when the part sees heat.
S275MChoose it when the part is bent, formed or impact-loaded, or when it will be welded.
34MnB5 vs S275M: 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.
Shear Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Vickers
Compressive Strength
Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Bulk Modulus 160 GPa23.2 Msi
Physical
Density and transition temperatures.
Melting Point (Solidus)
Liquidus Temperature
Same in both: Density 7.85 g/cm³0.28 lb/in³
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Max Service Temperature (continuous)
Min Service Temperature
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Brazeability / Solderability
Polishability
Castability
Sustainability
Primary-production footprint per kilogram.
Embodied Carbon (primary production)
Typical Recycled Content
Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Water 40 L/kg4.8 gal/lb
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
Same in both: Specific Stiffness (E / density) 26.8 MN·m/kg
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 | 34MnB5 | S275M |
|---|---|---|
| Sheet metal | Yes | — |
| Default condition | CR | — |
| Relative cost | $$ Standard | $ Budget |
| Min. machined wall | — | — |
| Best machined surface | — | — |
| Black Oxide | Yes | — |
| Cerakote | Yes | — |
| Chrome Plating | Yes | — |
| E-Coating | Yes | — |
| Hot-Dip Galvanizing | Yes | — |
| Nickel Plating | Yes | — |
| PTFE Coating | Yes | — |
| Painting | Yes | — |
| Powder Coating | Yes | — |
| Tin Plating | Yes | — |
| Zinc Plating | Yes | — |
| Zinc-Flake (Dip-Spin) Coating | Yes | — |
| Zinc-Nickel Plating | 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.
34MnB5 vs S275M — frequently asked
Is 34MnB5 stronger than S275M?
Yes. 34MnB5 has a typical yield strength of 420 MPa (60.9 ksi) against 300 MPa (43.5 ksi) for S275M — about 40% more. Tensile strength is 620 MPa (89.9 ksi) vs 440 MPa (63.8 ksi).
Which is cheaper, 34MnB5 or S275M?
S275M is the lower-cost material: it sits in the budget tier ($) while 34MnB5 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 is easier to machine, 34MnB5 or S275M?
S275M, by a small margin. Both rate good for machinability — 62/100 against 55/100 for 34MnB5; for welding the order is S275M first (excellent, 92/100) then 34MnB5 (good, 55/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 34MnB5 and S275M 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.