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Steel 9SiCr vs A2

Steel · grade comparison

Steel 9SiCr and A2 are both steel grades. Both yield at about 450 MPa — strength does not separate them. A2 is the more ductile: elongation 22% versus 18% for 9SiCr. A2 runs hotter in service (425°C vs 300°C continuous) and 9SiCr conducts heat better (32 W/m·K vs 26 W/m·K). On the shop floor, 9SiCr sits in a lower cost tier (standard, $$) than A2 (premium, $$$).

9SiCrChoose it when cost is the deciding factor.

A2Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

9SiCr vs A2: properties

9SiCrA2

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

210 GPa30.5 Msi
203 GPa29.4 Msi

Shear Modulus

81 GPa11.7 Msi
78 GPa11.3 Msi

Bulk Modulus

165 GPa23.9 Msi
160 GPa23.2 Msi

Poisson's Ratio

0.29
0.28

Tensile Strength (Ultimate)

760 MPa110 ksi
740 MPa107 ksi

Yield Strength (0.2% offset)

450 MPa65.3 ksi
470 MPa68.2 ksi

Elongation at Break

18%
22%

Reduction in Area

35%
45%

Compressive Strength

900 MPa131 ksi
500 MPa72.5 ksi

Shear Strength

460 MPa66.7 ksi
450 MPa65.3 ksi

Fatigue Strength (Endurance Limit)

350 MPa50.8 ksi
330 MPa47.9 ksi

Charpy V-Notch Impact (RT)

15 J11.1 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

220 HB
217 HB

Hardness, Rockwell B

97 HRB
96 HRB

Same in both: Hardness, Vickers 230 HV

Physical

Density and transition temperatures.

Density

7.75 g/cm³0.28 lb/in³
7.86 g/cm³0.28 lb/in³

Liquidus Temperature

1,470°C2,678 °F
1,465°C2,669 °F

Same in both: Melting Point (Solidus) 1,420°C2,588 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

32 W/m·K18.5 BTU/hr·ft·°F
26 W/m·K15 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

11.5 µm/m·K6.4 µin/in·°F
10.7 µm/m·K5.9 µin/in·°F

Latent Heat of Fusion

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

Max Service Temperature (continuous)

300°C572 °F
425°C797 °F

Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Min Service Temperature -30°C-22 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

5.7 % IACS
2.7 % IACS

Electrical Resistivity

3×10⁻⁷ Ω·m11.8 µΩ·in
6.5×10⁻⁷ Ω·m25.6 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

12 / 100
20 / 100

Manufacturability

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

Machinability Rating (AISI 1212 = 100 %)

45%
60%

Weldability

12 / 100
20 / 100

Formability (cold)

30 / 100
35 / 100

Castability

30 / 100
20 / 100

Brazeability / Solderability

45 / 100
40 / 100

Polishability

75 / 100
70 / 100

Same in both: Machinability 45 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

34 MJ/kg14,617 BTU/lb
36 MJ/kg15,477 BTU/lb

Embodied Carbon (primary production)

2.4 kg CO₂/kg
2.6 kg CO₂/kg

Embodied Water

60 L/kg7.2 gal/lb
65 L/kg7.8 gal/lb

Typical Recycled Content

30%
35%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

98 kN·m/kg
94 kN·m/kg

Specific Stiffness (E / density)

27.1 MN·m/kg
25.8 MN·m/kg

Modulus of Resilience

482 kJ/m³
544 kJ/m³

Thermal Diffusivity

9 mm²/s
7.2 mm²/s

Thermal Shock Resistance Index

10
9

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 scaleA29SiCr

Manufacturing and finishing

Capability9SiCrA2
CNC machining—Yes
Default condition—Annealed
Relative cost$$ Standard$$$ 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.

9SiCr vs A2 — frequently asked

What is the difference between 9SiCr and A2?

Steel 9SiCr and A2 are both steel grades. Both yield at about 450 MPa — strength does not separate them. A2 is the more ductile: elongation 22% versus 18% for 9SiCr.

Which is cheaper, 9SiCr or A2?

9SiCr is the lower-cost material: it sits in the standard tier ($$) while A2 is premium ($$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which welds better, 9SiCr or A2?

A2. Its weldability rates poor (20/100) against not recommended (12/100) for 9SiCr.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 9SiCr and A2 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.