FabDigitFabDigit

Stainless Steel 303 vs 305

Stainless Steel · grade comparison

Stainless Steel 303 and 305 are both stainless steel grades. 303 is the stronger of the two: yield strength 450 MPa (65.3 ksi) against 260 MPa (37.7 ksi) for 305, about 73% more; tensile strength follows at 655 MPa (95 ksi) vs 585 MPa (84.8 ksi). In exchange, 305 is the more ductile: elongation 50% versus 30% for 303, and 303 is harder (240 HB vs 150 HB). On the shop floor, 303 machines more easily (very good vs fair) and 305 welds better (very good vs poor).

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

305Choose it when the part is bent, formed or impact-loaded, or when it will be welded.

303 vs 305: properties

303305

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

655 MPa95 ksi
585 MPa84.8 ksi

Yield Strength (0.2% offset)

450 MPa65.3 ksi
260 MPa37.7 ksi

Elongation at Break

30%
50%

Reduction in Area

50%
65%

Compressive Strength

450 MPa65.3 ksi
260 MPa37.7 ksi

Fatigue Strength (Endurance Limit)

270 MPa39.2 ksi
250 MPa36.3 ksi

Fracture Toughness (K_IC)

100 MPa·√m91 ksi·√in
220 MPa·√m200 ksi·√in

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
160 J118 ft·lbf

Hardness, Brinell

240 HB
150 HB

Hardness, Rockwell B

99 HRB
80 HRB

Hardness, Vickers

250 HV
160 HV

Same in both: Elastic (Young's) Modulus 193 GPa28 Msi · Shear Modulus 77 GPa11.2 Msi · Bulk Modulus 140 GPa20.3 Msi · Poisson's Ratio 0.29 · Shear Strength 420 MPa60.9 ksi

Physical

Density and transition temperatures.

Density

7.9 g/cm³0.29 lb/in³
8 g/cm³0.29 lb/in³

Liquidus Temperature

1,420°C2,588 °F
1,450°C2,642 °F

Same in both: Melting Point (Solidus) 1,400°C2,552 °F

Thermal

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

Thermal Expansion (CTE, 20–100 °C)

17.3 µm/m·K9.6 µin/in·°F
17.2 µm/m·K9.6 µin/in·°F

Latent Heat of Fusion

275 J/g118 BTU/lb
285 J/g123 BTU/lb

Min Service Temperature

-100°C-148 °F
-196°C-321 °F

Same in both: Thermal Conductivity 16.2 W/m·K9.4 BTU/hr·ft·°F · Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Max Service Temperature (continuous) 760°C1,400 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 2.4 % IACS · Electrical Resistivity 7.2×10⁻⁷ Ω·m28.3 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.1 V
-0.08 V

Corrosion Resistance

58 / 100
66 / 100

Manufacturability

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

Machinability

72 / 100
38 / 100

Machinability Rating (AISI 1212 = 100 %)

78%
40%

Weldability

25 / 100
78 / 100

Formability (cold)

40 / 100
95 / 100

Brazeability / Solderability

60 / 100
70 / 100

Polishability

40 / 100
85 / 100

Castability

—
40 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

53 MJ/kg22,786 BTU/lb
82 MJ/kg35,254 BTU/lb

Embodied Carbon (primary production)

5.5 kg CO₂/kg
6.2 kg CO₂/kg

Embodied Water

150 L/kg18 gal/lb
210 L/kg25.2 gal/lb

Typical Recycled Content

65%
60%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

83 kN·m/kg
73 kN·m/kg

Specific Stiffness (E / density)

24.4 MN·m/kg
24.1 MN·m/kg

Modulus of Resilience

525 kJ/m³
175 kJ/m³

Same in both: Thermal Diffusivity 4.1 mm²/s · 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 scale303305

Manufacturing and finishing

Capability303305
CNC machiningYes—
Sheet metal—Yes
Default conditionCold DrawnAnnealed
Relative cost$$$ Premium$$$ Premium
Min. machined wall0.8 mm—
Best machined surfaceRa 1.6 µm—
AlCrNYes—
AlTiNYes—
CVD Al2O3Yes—
CVD TiCNYes—
CVD TiNYes—
CrNYes—
DLCYes—
HVOF CoatingYes—
MoS2Yes—
Multilayer CVDYes—
TiAlNYes—
TiB2Yes—
TiCNYes—
TiNYes—
WC/CYes—
ZrNYes—

They share 16 finishes: Black Oxide, Cerakote, Chrome Plating, Electroless Nickel (EN), Electropolishing, Epoxy Coating, Gold Plating, Hard Chrome Plating, Nickel Plating, PTFE Coating, Painting, Passivation (Stainless Steel) and 4 more.

303 vs 305 — frequently asked

Is 303 stronger than 305?

Yes. 303 has a typical yield strength of 450 MPa (65.3 ksi) against 260 MPa (37.7 ksi) for 305 — about 73% more. Tensile strength is 655 MPa (95 ksi) vs 585 MPa (84.8 ksi).

Which is cheaper, 303 or 305?

Both sit in the same relative cost tier ($$$, premium); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, 303 or 305?

303. Its machinability rates very good (72/100) against fair (38/100) for 305; for welding the order is 305 first (very good, 78/100) then 303 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 303 and 305 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.