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Stainless Steel 303 vs RA85H

Stainless Steel · grade comparison

Stainless Steel 303 and RA85H are both stainless steel grades. 303 is the stronger of the two: yield strength 450 MPa (65.3 ksi) against 345 MPa (50 ksi) for RA85H, about 30% more. In exchange, RA85H is the more ductile: elongation 45% versus 30% for 303, and 303 is harder (240 HB vs 180 HB). RA85H runs hotter in service (1,095°C vs 760°C continuous) and 303 conducts heat better (16.2 W/m·K vs 12.6 W/m·K). On the shop floor, 303 machines more easily (very good vs poor), RA85H welds better (good vs poor), and 303 sits in a lower cost tier (premium, $$$) than RA85H (high, $$$$).

303Choose it when strength drives the design, or when the part is machined in volume.

RA85HChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

303 vs RA85H: properties

303RA85H

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

193 GPa28 Msi
196 GPa28.4 Msi

Shear Modulus

77 GPa11.2 Msi
76 GPa11 Msi

Bulk Modulus

140 GPa20.3 Msi
160 GPa23.2 Msi

Yield Strength (0.2% offset)

450 MPa65.3 ksi
345 MPa50 ksi

Elongation at Break

30%
45%

Reduction in Area

50%
55%

Compressive Strength

450 MPa65.3 ksi
345 MPa50 ksi

Shear Strength

420 MPa60.9 ksi
440 MPa63.8 ksi

Fatigue Strength (Endurance Limit)

270 MPa39.2 ksi
260 MPa37.7 ksi

Fracture Toughness (K_IC)

100 MPa·√m91 ksi·√in
200 MPa·√m182 ksi·√in

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
110 J81.1 ft·lbf

Hardness, Brinell

240 HB
180 HB

Hardness, Rockwell B

99 HRB
88 HRB

Hardness, Vickers

250 HV
190 HV

Same in both: Poisson's Ratio 0.29 · Tensile Strength (Ultimate) 655 MPa95 ksi

Physical

Density and transition temperatures.

Density

7.9 g/cm³0.29 lb/in³
7.72 g/cm³0.28 lb/in³

Melting Point (Solidus)

1,400°C2,552 °F
1,350°C2,462 °F

Liquidus Temperature

1,420°C2,588 °F
1,400°C2,552 °F

Thermal

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

Thermal Conductivity

16.2 W/m·K9.4 BTU/hr·ft·°F
12.6 W/m·K7.3 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

17.3 µm/m·K9.6 µin/in·°F
15.6 µm/m·K8.7 µin/in·°F

Latent Heat of Fusion

275 J/g118 BTU/lb
—

Max Service Temperature (continuous)

760°C1,400 °F
1,095°C2,003 °F

Min Service Temperature

-100°C-148 °F
—

Same in both: Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F

Electrical

Conductivity and insulation.

Electrical Conductivity

2.4 % IACS
1.7 % IACS

Electrical Resistivity

7.2×10⁻⁷ Ω·m28.3 µΩ·in
1×10⁻⁶ Ω·m39.4 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

58 / 100
62 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.1 V

Manufacturability

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

Machinability

72 / 100
28 / 100

Machinability Rating (AISI 1212 = 100 %)

78%
32%

Weldability

25 / 100
55 / 100

Formability (cold)

40 / 100
55 / 100

Brazeability / Solderability

60 / 100
55 / 100

Polishability

40 / 100
60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

53 MJ/kg22,786 BTU/lb
58 MJ/kg24,936 BTU/lb

Embodied Carbon (primary production)

5.5 kg CO₂/kg
5.2 kg CO₂/kg

Embodied Water

150 L/kg18 gal/lb
200 L/kg24 gal/lb

Typical Recycled Content

65%
60%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

83 kN·m/kg
85 kN·m/kg

Specific Stiffness (E / density)

24.4 MN·m/kg
25.4 MN·m/kg

Modulus of Resilience

525 kJ/m³
304 kJ/m³

Thermal Diffusivity

4.1 mm²/s
3.3 mm²/s

Same in both: Thermal Shock Resistance Index 3

Strength versus weight

Yield strength against density for every stainless steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

3005007001,0001,5002,0007.27.47.67.888.2Density (g/cm³)Yield strength (MPa) — log scale303RA85H

Manufacturing and finishing

Capability303RA85H
CNC machiningYes—
Default conditionCold Drawn—
Relative cost$$$ Premium$$$$ High
Min. machined wall0.8 mm—
Best machined surfaceRa 1.6 µm—
AlCrNYes—
AlTiNYes—
Black OxideYes—
CVD Al2O3Yes—
CVD TiCNYes—
CVD TiNYes—
CerakoteYes—
Chrome PlatingYes—
CrNYes—
DLCYes—
ElectropolishingYes—
HVOF CoatingYes—
MoS2Yes—
Multilayer CVDYes—
Nickel PlatingYes—
PTFE CoatingYes—
PaintingYes—
Passivation (Stainless Steel)Yes—

They share 7 finishes: Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Pickling, Plasma Spray, Silver Plating.

303 vs RA85H — frequently asked

Is 303 stronger than RA85H?

Yes. 303 has a typical yield strength of 450 MPa (65.3 ksi) against 345 MPa (50 ksi) for RA85H — about 30% more. Tensile strength is 655 MPa (95 ksi) vs 655 MPa (95 ksi).

Which is cheaper, 303 or RA85H?

303 is the lower-cost material: it sits in the premium tier ($$$) while RA85H is high ($$$$). 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, 303 or RA85H?

303. Its machinability rates very good (72/100) against poor (28/100) for RA85H; for welding the order is RA85H first (good, 55/100) then 303 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 303 and RA85H 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.