Steel 30CrMnSi vs AR400
Steel · grade comparison
Steel 30CrMnSi and AR400 are both steel grades. AR400 is the stronger of the two: yield strength 1,050 MPa (152 ksi) against 900 MPa (131 ksi) for 30CrMnSi, about 17% more; tensile strength follows at 1,250 MPa (181 ksi) vs 1,120 MPa (162 ksi). AR400 is harder — 400 HB against 340 HB for 30CrMnSi — which matters for wear surfaces and threads. 30CrMnSi runs hotter in service (400°C vs 250°C continuous) and AR400 conducts heat better (42 W/m·K vs 37 W/m·K). On the shop floor, 30CrMnSi machines more easily (fair vs poor), AR400 welds better (good vs fair), and 30CrMnSi sits in a lower cost tier (budget, $) than AR400 (premium, $$$).
30CrMnSiChoose it when the part sees heat, or when the part is machined in volume.
AR400Choose it when strength drives the design, or when surface hardness matters.
30CrMnSi vs AR400: 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.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Reduction in Area
Compressive Strength
Shear Strength
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Elongation at Break 11% · Fatigue Strength (Endurance Limit) 520 MPa75.4 ksi
Physical
Density and transition temperatures.
Liquidus Temperature
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 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)
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 12 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Brazeability / Solderability
Polishability
Same in both: Formability (cold) 25 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Typical Recycled Content
Same in both: Embodied Carbon (primary production) 2.3 kg CO₂/kg · Embodied Water 45 L/kg5.4 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) 26.1 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 | 30CrMnSi | AR400 |
|---|---|---|
| CNC machining | — | Yes |
| Sheet metal | — | Yes |
| Default condition | — | Q&T |
| Relative cost | $ Budget | $$$ Premium |
| 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.
30CrMnSi vs AR400 — frequently asked
Is AR400 stronger than 30CrMnSi?
Yes. AR400 has a typical yield strength of 1,050 MPa (152 ksi) against 900 MPa (131 ksi) for 30CrMnSi — about 17% more. Tensile strength is 1,250 MPa (181 ksi) vs 1,120 MPa (162 ksi).
Which is cheaper, 30CrMnSi or AR400?
30CrMnSi is the lower-cost material: it sits in the budget tier ($) while AR400 is premium ($$$). 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, 30CrMnSi or AR400?
30CrMnSi. Its machinability rates fair (40/100) against poor (22/100) for AR400; for welding the order is AR400 first (good, 55/100) then 30CrMnSi (fair, 40/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 30CrMnSi and AR400 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.