Steel 34MnB5 vs S420N
Steel · grade comparison
Steel 34MnB5 and S420N are both steel grades. 34MnB5 is the stronger of the two: tensile strength 620 MPa (89.9 ksi) against 570 MPa (82.7 ksi) for S420N, about 9% more. In exchange, S420N is the more ductile: elongation 23% versus 14% for 34MnB5, and 34MnB5 is harder (185 HB vs 170 HB). 34MnB5 runs hotter in service (400°C vs 350°C continuous). On the shop floor, S420N welds better (very good vs good) and S420N sits in a lower cost tier (budget, $) than 34MnB5 (standard, $$).
34MnB5Choose it when strength drives the design, or when the part sees heat.
S420NChoose it when the part is bent, formed or impact-loaded, or when it will be welded.
34MnB5 vs S420N: 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
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Max Service Temperature (continuous)
Min Service Temperature
Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Galvanic Potential (seawater, vs SCE)
Same in both: Corrosion Resistance 11 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability Rating (AISI 1212 = 100 %)
Weldability
Brazeability / Solderability
Polishability
Castability
Same in both: Machinability 55 / 100 · Formability (cold) 60 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Carbon (primary production)
Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Water 40 L/kg4.8 gal/lb · Typical Recycled Content 25%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Modulus of Resilience
Thermal Diffusivity
Same in both: Specific Stiffness (E / density) 26.8 MN·m/kg · Thermal Shock Resistance Index 10
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 | S420N |
|---|---|---|
| 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 S420N — frequently asked
Is 34MnB5 stronger than S420N?
Yes. 34MnB5 has a typical tensile strength of 620 MPa (89.9 ksi) against 570 MPa (82.7 ksi) for S420N — about 9% more.
Which is cheaper, 34MnB5 or S420N?
S420N 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 welds better, 34MnB5 or S420N?
S420N. Its weldability rates very good (80/100) against good (55/100) for 34MnB5.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 34MnB5 and S420N 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.