Steel 51100 vs SUJ2
Steel · grade comparison
Steel 51100 and SUJ2 are both steel grades. Both yield at about 400 MPa — strength does not separate them. 51100 runs hotter in service (400°C vs 200°C continuous) and 51100 conducts electricity better (8 % IACS vs 7 % IACS). On the shop floor, 51100 sits in a lower cost tier (budget, $) than SUJ2 (standard, $$).
51100Choose it when the part sees heat, or when cost is the deciding factor.
51100 vs SUJ2: 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)
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Rockwell B
Same in both: Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Elongation at Break 25% · Reduction in Area 45% · Hardness, Brinell 192 HB · Hardness, Vickers 200 HV
Physical
Density and transition temperatures.
Melting Point (Solidus)
Same in both: Density 7.81 g/cm³0.28 lb/in³ · Liquidus Temperature 1,460°C2,660 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Min Service Temperature
Same in both: Thermal Conductivity 46 W/m·K26.6 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.9 µm/m·K6.6 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Galvanic Potential (seawater, vs SCE)
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Formability (cold)
Polishability
Same in both: Machinability 45 / 100 · Machinability Rating (AISI 1212 = 100 %) 40% · Weldability 12 / 100 · Castability 30 / 100 · Brazeability / Solderability 35 / 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
Same in both: Thermal Diffusivity 12.8 mm²/s · Thermal Shock Resistance Index 12
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 | 51100 | SUJ2 |
|---|---|---|
| CNC machining | — | Yes |
| Sheet metal | — | Yes |
| Default condition | — | Annealed |
| Relative cost | $ Budget | $$ Standard |
| 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.
51100 vs SUJ2 — frequently asked
What is the difference between 51100 and SUJ2?
Steel 51100 and SUJ2 are both steel grades. Both yield at about 400 MPa — strength does not separate them. 51100 runs hotter in service (400°C vs 200°C continuous) and 51100 conducts electricity better (8 % IACS vs 7 % IACS).
Which is cheaper, 51100 or SUJ2?
51100 is the lower-cost material: it sits in the budget tier ($) while SUJ2 is standard ($$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
When should I choose 51100 over SUJ2?
Pick 51100 when the part sees heat, or when cost is the deciding factor.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 51100 and SUJ2 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.