Steel 15B35 vs SMnB420H
Steel · grade comparison
Steel 15B35 and SMnB420H are both steel grades. 15B35 is the stronger of the two: yield strength 620 MPa (89.9 ksi) against 355 MPa (51.5 ksi) for SMnB420H, about 75% more; tensile strength follows at 730 MPa (106 ksi) vs 560 MPa (81.2 ksi). In exchange, SMnB420H is the more ductile: elongation 26% versus 13% for 15B35, and 15B35 is harder (217 HB vs 170 HB). 15B35 conducts electricity better (9.5 % IACS vs 8.2 % IACS). On the shop floor, SMnB420H welds better (good vs fair).
15B35Choose it when strength drives the design.
SMnB420HChoose it when the part is bent, formed or impact-loaded, or when it will be welded.
15B35 vs SMnB420H: 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
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Fracture Toughness (K_IC)
Same in both: Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29
Physical
Density and transition temperatures.
Liquidus Temperature
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F
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
Same in both: Max Service Temperature (continuous) 350°C662 °F · Min Service Temperature -30°C-22 °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 10 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Brazeability / Solderability
Polishability
Same in both: Machinability Rating (AISI 1212 = 100 %) 65%
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 30%
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 | 15B35 | SMnB420H |
|---|---|---|
| Default condition | — | — |
| Relative cost | $ Budget | $ Budget |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Both take the same 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.
15B35 vs SMnB420H — frequently asked
Is 15B35 stronger than SMnB420H?
Yes. 15B35 has a typical yield strength of 620 MPa (89.9 ksi) against 355 MPa (51.5 ksi) for SMnB420H — about 75% more. Tensile strength is 730 MPa (106 ksi) vs 560 MPa (81.2 ksi).
Which is cheaper, 15B35 or SMnB420H?
Both sit in the same relative cost tier ($, budget); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, 15B35 or SMnB420H?
SMnB420H, by a small margin. Both rate good for machinability — 62/100 against 55/100 for 15B35; for welding the order is SMnB420H first (good, 55/100) then 15B35 (fair, 40/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 15B35 and SMnB420H 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.