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Cobalt-Chrome Alloy Stellite 21 As Cast vs Stellite 21-HIP

Cobalt-Chrome Alloy · Stellite 21 temper comparison

Stellite 21 As Cast and Stellite 21-HIP are two conditions of the same cobalt-chrome alloy grade, Stellite 21: As Cast versus HIP (hot isostatic pressed). The chemistry is identical, so every difference below comes from the condition. Stellite 21-HIP is the stronger of the two: yield strength 640 MPa (92.8 ksi) against 495 MPa (71.8 ksi) for Stellite 21 As Cast, about 29% more; tensile strength follows at 950 MPa (138 ksi) vs 710 MPa (103 ksi). Stellite 21-HIP is the more ductile: elongation 16% versus 9% for Stellite 21 As Cast, and Stellite 21-HIP is harder (320 HB vs 300 HB).

Stellite 21-HIPChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.

Stellite 21 As Cast vs Stellite 21-HIP: properties

Stellite 21 As CastStellite 21-HIP

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

248 GPa36 Msi
250 GPa36.3 Msi

Tensile Strength (Ultimate)

710 MPa103 ksi
950 MPa138 ksi

Yield Strength (0.2% offset)

495 MPa71.8 ksi
640 MPa92.8 ksi

Elongation at Break

9%
16%

Reduction in Area

9%
18%

Compressive Strength

1,250 MPa181 ksi
1,400 MPa203 ksi

Shear Strength

490 MPa71.1 ksi
620 MPa89.9 ksi

Fatigue Strength (Endurance Limit)

240 MPa34.8 ksi
300 MPa43.5 ksi

Fracture Toughness (K_IC)

50 MPa·√m45.5 ksi·√in
70 MPa·√m63.7 ksi·√in

Charpy V-Notch Impact (RT)

14 J10.3 ft·lbf
24 J17.7 ft·lbf

Hardness, Brinell

300 HB
320 HB

Hardness, Rockwell C

32 HRC
34 HRC

Hardness, Vickers

320 HV
340 HV

Same in both: Shear Modulus 95 GPa13.8 Msi · Bulk Modulus 200 GPa29 Msi · Poisson's Ratio 0.3

Physical

Density and transition temperatures.

Same in both: Density 8.33 g/cm³0.3 lb/in³ · Melting Point (Solidus) 1,186°C2,167 °F · Liquidus Temperature 1,383°C2,521 °F

Thermal

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

Same in both: Thermal Conductivity 14.8 W/m·K8.6 BTU/hr·ft·°F · Specific Heat Capacity 423 J/kg·K0.1 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 14.2 µm/m·K7.9 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Max Service Temperature (continuous) 760°C1,400 °F · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 2 % IACS · Electrical Resistivity 8.6×10⁻⁷ Ω·m33.9 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

80 / 100
82 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.3 V

Manufacturability

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

Machinability

15 / 100
16 / 100

Machinability Rating (AISI 1212 = 100 %)

10%
11%

Weldability

55 / 100
58 / 100

Formability (cold)

20 / 100
25 / 100

Same in both: Castability 78 / 100 · Brazeability / Solderability 55 / 100 · Polishability 85 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 145 MJ/kg62,339 BTU/lb · Embodied Carbon (primary production) 10 kg CO₂/kg · Embodied Water 420 L/kg50.3 gal/lb · Typical Recycled Content 25%

Strength versus weight

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

5007001,0001,5002,0008.28.48.68.89Density (g/cm³)Yield strength (MPa) — log scaleStellite 21

Stellite 21 As Cast vs Stellite 21-HIP — frequently asked

Is Stellite 21-HIP stronger than Stellite 21 As Cast?

Yes. Stellite 21-HIP has a typical yield strength of 640 MPa (92.8 ksi) against 495 MPa (71.8 ksi) for Stellite 21 As Cast — about 29% more. Tensile strength is 950 MPa (138 ksi) vs 710 MPa (103 ksi).

Which condition does FabDigit quote by default, As Cast or HIP?

As Cast is the default Stellite 21 condition in the FabDigit quote flow. The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.

When should I choose Stellite 21 As Cast over Stellite 21-HIP?

Pick Stellite 21-HIP when strength drives the design, or when the part is bent, formed or impact-loaded.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Stellite 21 As Cast and Stellite 21-HIP 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.