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Steel 30CrMnSiA vs AR400

Steel · grade comparison

Steel 30CrMnSiA and AR400 are both steel grades. AR400 is the stronger of the two: yield strength 1,050 MPa (152 ksi) against 930 MPa (135 ksi) for 30CrMnSiA, about 13% more; tensile strength follows at 1,250 MPa (181 ksi) vs 1,130 MPa (164 ksi). AR400 is harder — 400 HB against 340 HB for 30CrMnSiA — which matters for wear surfaces and threads. 30CrMnSiA runs hotter in service (400°C vs 250°C continuous). On the shop floor, 30CrMnSiA machines more easily (fair vs poor), 30CrMnSiA forms better (fair vs poor), and 30CrMnSiA sits in a lower cost tier (budget, $) than AR400 (premium, $$$).

30CrMnSiAChoose 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.

30CrMnSiA vs AR400: properties

30CrMnSiAAR400

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

210 GPa30.5 Msi
205 GPa29.7 Msi

Shear Modulus

81 GPa11.7 Msi
80 GPa11.6 Msi

Bulk Modulus

165 GPa23.9 Msi
160 GPa23.2 Msi

Tensile Strength (Ultimate)

1,130 MPa164 ksi
1,250 MPa181 ksi

Yield Strength (0.2% offset)

930 MPa135 ksi
1,050 MPa152 ksi

Elongation at Break

12%
11%

Reduction in Area

50%
40%

Compressive Strength

960 MPa139 ksi
1,100 MPa160 ksi

Shear Strength

680 MPa98.6 ksi
780 MPa113 ksi

Fracture Toughness (K_IC)

80 MPa·√m72.8 ksi·√in
70 MPa·√m63.7 ksi·√in

Charpy V-Notch Impact (RT)

60 J44.3 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

340 HB
400 HB

Hardness, Rockwell C

36 HRC
43 HRC

Hardness, Vickers

355 HV
420 HV

Same in both: Poisson's Ratio 0.29 · Fatigue Strength (Endurance Limit) 520 MPa75.4 ksi

Physical

Density and transition temperatures.

Liquidus Temperature

1,490°C2,714 °F
1,500°C2,732 °F

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

38 W/m·K22 BTU/hr·ft·°F
42 W/m·K24.3 BTU/hr·ft·°F

Specific Heat Capacity

480 J/kg·K0.11 BTU/lb·°F
470 J/kg·K0.11 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

11.3 µm/m·K6.3 µin/in·°F
12 µm/m·K6.7 µin/in·°F

Latent Heat of Fusion

260 J/g112 BTU/lb
250 J/g107 BTU/lb

Max Service Temperature (continuous)

400°C752 °F
250°C482 °F

Min Service Temperature

-60°C-76 °F
-20°C-4 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7.2 % IACS
8 % IACS

Electrical Resistivity

2.4×10⁻⁷ Ω·m9.45 µΩ·in
2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.6 V
—

Same in both: Corrosion Resistance 12 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

42 / 100
22 / 100

Machinability Rating (AISI 1212 = 100 %)

45%
20%

Formability (cold)

35 / 100
25 / 100

Brazeability / Solderability

55 / 100
20 / 100

Polishability

65 / 100
55 / 100

Same in both: Weldability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

34 MJ/kg14,617 BTU/lb
28 MJ/kg12,038 BTU/lb

Embodied Carbon (primary production)

2.4 kg CO₂/kg
2.3 kg CO₂/kg

Embodied Water

60 L/kg7.2 gal/lb
45 L/kg5.4 gal/lb

Same in both: Typical Recycled Content 25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

144 kN·m/kg
159 kN·m/kg

Specific Stiffness (E / density)

26.8 MN·m/kg
26.1 MN·m/kg

Modulus of Resilience

2,059 kJ/m³
2,689 kJ/m³

Thermal Diffusivity

10.1 mm²/s
11.4 mm²/s

Thermal Shock Resistance Index

18
21

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.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scaleAR40030CrMnSiA

Manufacturing and finishing

Capability30CrMnSiAAR400
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.

30CrMnSiA vs AR400 — frequently asked

Is AR400 stronger than 30CrMnSiA?

Yes. AR400 has a typical yield strength of 1,050 MPa (152 ksi) against 930 MPa (135 ksi) for 30CrMnSiA — about 13% more. Tensile strength is 1,250 MPa (181 ksi) vs 1,130 MPa (164 ksi).

Which is cheaper, 30CrMnSiA or AR400?

30CrMnSiA 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, 30CrMnSiA or AR400?

30CrMnSiA. Its machinability rates fair (42/100) against poor (22/100) for AR400.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 30CrMnSiA 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.