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Stainless Steel Alloy 20 vs S33228

Stainless Steel · grade comparison

Stainless Steel Alloy 20 and S33228 are both stainless steel grades. Alloy 20 is the stronger of the two: yield strength 310 MPa (45 ksi) against 280 MPa (40.6 ksi) for S33228, about 11% more. S33228 is harder — 170 HB against 160 HB for Alloy 20 — which matters for wear surfaces and threads. S33228 runs hotter in service (1,100°C vs 500°C continuous). On the shop floor, Alloy 20 machines more easily (fair vs poor), Alloy 20 welds better (very good vs good), and Alloy 20 forms better (very good vs good).

Alloy 20Choose it when strength drives the design, or when the part is machined in volume.

S33228Choose it when surface hardness matters, or when the part sees heat.

Alloy 20 vs S33228: properties

Alloy 20S33228

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

193 GPa28 Msi
190 GPa27.6 Msi

Shear Modulus

74 GPa10.7 Msi
73 GPa10.6 Msi

Bulk Modulus

160 GPa23.2 Msi
150 GPa21.8 Msi

Poisson's Ratio

0.3
0.29

Yield Strength (0.2% offset)

310 MPa45 ksi
280 MPa40.6 ksi

Elongation at Break

40%
42%

Reduction in Area

60%
55%

Shear Strength

415 MPa60.2 ksi
390 MPa56.6 ksi

Fatigue Strength (Endurance Limit)

260 MPa37.7 ksi
250 MPa36.3 ksi

Charpy V-Notch Impact (RT)

190 J140 ft·lbf
140 J103 ft·lbf

Hardness, Brinell

160 HB
170 HB

Hardness, Rockwell B

85 HRB
86 HRB

Hardness, Vickers

—
180 HV

Same in both: Tensile Strength (Ultimate) 620 MPa89.9 ksi

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

1,370°C2,498 °F
1,340°C2,444 °F

Liquidus Temperature

1,425°C2,597 °F
1,390°C2,534 °F

Thermal

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

Thermal Conductivity

12 W/m·K6.9 BTU/hr·ft·°F
11.5 W/m·K6.6 BTU/hr·ft·°F

Specific Heat Capacity

500 J/kg·K0.12 BTU/lb·°F
450 J/kg·K0.11 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

14.8 µm/m·K8.2 µin/in·°F
15 µm/m·K8.3 µin/in·°F

Latent Heat of Fusion

285 J/g123 BTU/lb
270 J/g116 BTU/lb

Max Service Temperature (continuous)

500°C932 °F
1,100°C2,012 °F

Min Service Temperature

-196°C-321 °F
-100°C-148 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

1.6 % IACS
1.7 % IACS

Electrical Resistivity

1.08×10⁻⁶ Ω·m42.5 µΩ·in
1×10⁻⁶ Ω·m39.4 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.08 V
-0.1 V

Corrosion Resistance

80 / 100
55 / 100

Manufacturability

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

Machinability

38 / 100
25 / 100

Machinability Rating (AISI 1212 = 100 %)

40%
25%

Weldability

80 / 100
65 / 100

Formability (cold)

72 / 100
60 / 100

Castability

55 / 100
40 / 100

Brazeability / Solderability

60 / 100
55 / 100

Polishability

75 / 100
65 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

100 MJ/kg42,992 BTU/lb
90 MJ/kg38,693 BTU/lb

Embodied Carbon (primary production)

7.5 kg CO₂/kg
7 kg CO₂/kg

Embodied Water

200 L/kg24 gal/lb
180 L/kg21.6 gal/lb

Typical Recycled Content

45%
40%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

77 kN·m/kg
78 kN·m/kg

Specific Stiffness (E / density)

23.9 MN·m/kg
24.1 MN·m/kg

Modulus of Resilience

249 kJ/m³
206 kJ/m³

Thermal Diffusivity

3 mm²/s
3.2 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 scaleAlloy 20S33228

Manufacturing and finishing

CapabilityAlloy 20S33228
CNC machiningYes—
Sheet metalYes—
Default conditionAnnealed—
Relative cost$$$$$ Specialty$$$$ 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.

Alloy 20 vs S33228 — frequently asked

Is Alloy 20 stronger than S33228?

Yes. Alloy 20 has a typical yield strength of 310 MPa (45 ksi) against 280 MPa (40.6 ksi) for S33228 — about 11% more. Tensile strength is 620 MPa (89.9 ksi) vs 620 MPa (89.9 ksi).

Which is cheaper, Alloy 20 or S33228?

S33228 is the lower-cost material: it sits in the high tier ($$$$) while Alloy 20 is specialty ($$$$$). 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, Alloy 20 or S33228?

Alloy 20. Its machinability rates fair (38/100) against poor (25/100) for S33228; for welding the order is Alloy 20 first (very good, 80/100) then S33228 (good, 65/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in Alloy 20 and S33228 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.