Cobalt-Chrome Alloy Stellite 6
UNS R30006 · also CoCrW Stellite
Stellite 6 (UNS R30006) is the most widely used Co-Cr-W-C hardfacing alloy, balancing wear, galling and corrosion resistance with hot hardness; wear performance is normally rated to about 500 °C and oxidation service to 800 °C.
Reference datasheet — Stellite 6 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the As Cast condition
Stellite 6 tempers and conditions
Stellite 6 is supplied in 5 conditions, soft to hard. As Cast is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
GTAW/PTA/oxy-acetylene hardfacing deposit | Pick for on-part hardfacing of valve seats, shafts and edges; hardness of the first layer drops with substrate dilution, so deposit two or more layers. | 520 | 800 | 1 | 41 HRC | 1.9 % IACS |
As CastDefault chill/investment cast bar, seat ring or casting | Default supply form for valve trim, seat rings and cast wear parts; maximum carbide content, lowest ductility. | 541 | 834 | 1 | 40 HRC | — |
hot rolled/forged wrought bar, plate or sheet | Choose when some ductility and toughness are needed alongside wear resistance (bushings, blades, wear plate); carbides are broken up and aligned. | 620 | 1,000 | 9 | 38 HRC | — |
Hot isostatic pressed | Choose for near-net-shape parts needing uniform fine carbides, higher strength and better toughness than cast Stellite 6. | 680 | 1,000 | 4 | 42 HRC | 1.9 % IACS |
laser powder-bed / laser cladding as-deposited | Pick for printed or laser-clad wear parts; rapid solidification gives fine dendrites, higher hardness and strength but residual stress and anisotropy. | 720 | 1,100 | 4 | 45 HRC | 1.8 % IACS |
Supply forms, finishes and certifications
Ways Stellite 6 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
HVOF | HVOF / Thermal Spray Coating | Coating |
What is Stellite 6?
Stellite 6 (UNS R30006) is the most widely used Co-Cr-W-C hardfacing alloy, balancing wear, galling and corrosion resistance with hot hardness; wear performance is normally rated to about 500 °C and oxidation service to 800 °C. It is supplied as castings, hot-worked bar, welded and HVOF-sprayed deposits, HIPed powder-metallurgy stock and additive-manufactured parts, typically at 40 HRC with 834 MPa tensile and 541 MPa yield strength. Ductility is essentially nil (about 1 % elongation) and machinability is very low (score 8), so parts are ground or EDM'd to size. Use it as an overlay on a tougher substrate where a fully cast component would be too brittle or too expensive. Stellite 6 has a density of 8.44 g/cm³ (0.305 lb/in³), lighter than 52% of cobalt-chrome alloy grades. It melts at 1,285°C (2,345 °F). Stellite 6 has a yield strength of 541 MPa (78.5 ksi) and a tensile strength of 834 MPa (121 ksi) — weaker than 54% of cobalt-chrome alloy grades. Elongation at break is 1% and the elastic modulus is 220 GPa (31.9 Msi).
What is Stellite 6 used for?
- Valve seats and valve trim
- Hardfacing rods and welding wire
- Pump sleeves and wear rings
- Extruder and screw flight overlays
- Cutting knives and saw teeth
- Bearing bushings and thrust washers
- Erosion shields on steam path parts
Advantages
- Readily welded — 55/100, better than 80% of cobalt-chrome alloy grades
Stellite 6 properties
Typical room-temperature values for Stellite 6-As Cast; bars are the position among cobalt-chrome alloy grades.
Physical3
Stellite 6 has a density of 8.44 g/cm³ (0.305 lb/in³), lighter than 52% of cobalt-chrome alloy grades. It melts at 1,285°C (2,345 °F).
Mechanical13
Stellite 6 has a yield strength of 541 MPa (78.5 ksi) and a tensile strength of 834 MPa (121 ksi) — weaker than 54% of cobalt-chrome alloy grades. Elongation at break is 1% and the elastic modulus is 220 GPa (31.9 Msi).
Thermal5
Stellite 6 is rated for continuous service to 800°C (1,472 °F). It conducts heat at 14.8 W/m·K (8.55 BTU/hr·ft·°F), better than 84% of cobalt-chrome alloy grades. Thermal expansion is 12.5 µm/m·K (6.94 µin/in·°F).
Electrical3
Stellite 6 conducts electricity at 1.9 % IACS, worse than 52% of cobalt-chrome alloy grades.
Chemical & Environmental3
Corrosion resistance is very good (70/100), worse than 71% of cobalt-chrome alloy grades.
Sustainability4
Producing a kilogram of Stellite 6 takes about 150 MJ of energy and emits 13 kg of CO₂ — less than 59% of cobalt-chrome alloy grades. Typical recycled content is 30%.
Manufacturability8
Stellite 6's machinability is not recommended (8/100, worse than 64% of cobalt-chrome alloy grades); weldability good (55/100); formability not recommended (5/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the cobalt-chrome alloy family
Yield strength against density for every cobalt-chrome alloy grade FabDigit runs. Stellite 6 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Stellite 6
Is Stellite 6 easy to machine?
Treat as a grinding/EDM material — cast Stellite 6 at 40 HRC work-hardens and abrades tools; if turning, use negative-rake CBN or C2 carbide, rigid setup, low speed (10–25 m/min), heavy feed and flood coolant.
Can Stellite 6 be welded?
Deposit by GTAW, PTA, oxy-acetylene or laser cladding with 200–350 °C preheat and slow cooling; expect fine transverse check cracks (usually acceptable), and use 2+ layers or a buffer layer on carbon/low-alloy steel to limit iron dilution.
Can Stellite 6 be formed, bent or molded?
No practical cold forming — parts are cast to near-net shape, PM/HIP consolidated, printed, or hot worked above ~1100 °C in the wrought grade.
Stellite 6 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Cr | 27 – 32 | 29 |
| W | 3.5 – 5.5 | 4.5 |
| Cforms Cr7C3 / M23C6 and W-rich carbides | 0.9 – 1.4 | 1.1 |
| Ni | ≤ 3 | 1 |
| Fe | ≤ 3 | 1.5 |
| Si | ≤ 2 | 1.1 |
| Mn | ≤ 2 | 1 |
| Mo | ≤ 1.5 | 0.5 |
| Cobalance, ~57–60 % | balance |
What surface finishes work on Stellite 6?
Finish by wet grinding, lapping or superfinishing for valve-seat flatness; do not anodize — surfaces are used bare or lightly passivated, and the alloy takes a mirror polish that improves erosion/sealing life.
Equivalent designations
Standards and trade names that resolve to Cobalt-Chrome Alloy Stellite 6 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- R30006
- Trade names
- CoCrW Stellite
- Similar grades
- ERCoCr-A
How much does Stellite 6 cost?
Stellite 6 is a specialty-cost cobalt-chrome alloy ($$$$$), pricier than about 99% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Stellite 6 — frequently asked
What is Stellite 6 used for?
Stellite 6 is typically used for valve seats and valve trim, hardfacing rods and welding wire, pump sleeves and wear rings, extruder and screw flight overlays, cutting knives and saw teeth and bearing bushings and thrust washers. In short: hardfacing cobalt alloy.
What is the yield strength of Stellite 6?
Stellite 6 has a typical yield strength of 541 MPa (78.5 ksi) and a tensile strength of 834 MPa (121 ksi) — weaker than 54% of cobalt-chrome alloy grades. Strength varies by condition: see the 5 listed tempers.
Is Stellite 6 easy to machine?
Not especially — machinability is rated not recommended (8/100, worse than 64% of cobalt-chrome alloy grades). Treat as a grinding/EDM material — cast Stellite 6 at 40 HRC work-hardens and abrades tools; if turning, use negative-rake CBN or C2 carbide, rigid setup, low speed (10–25 m/min), heavy feed and flood coolant.
Can Stellite 6 be welded?
Yes — weldability is rated good (55/100). Deposit by GTAW, PTA, oxy-acetylene or laser cladding with 200–350 °C preheat and slow cooling; expect fine transverse check cracks (usually acceptable), and use 2+ layers or a buffer layer on carbon/low-alloy steel to limit iron dilution.
What surface finishes work on Stellite 6?
Finish by wet grinding, lapping or superfinishing for valve-seat flatness; do not anodize — surfaces are used bare or lightly passivated, and the alloy takes a mirror polish that improves erosion/sealing life.
Can Stellite 6 be formed, bent or molded?
No practical cold forming — parts are cast to near-net shape, PM/HIP consolidated, printed, or hot worked above ~1100 °C in the wrought grade.
What is the maximum service temperature of Stellite 6?
Stellite 6 is rated for continuous use to about 800°C (1,472 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Stellite 6 As Cast and Stellite 6-HIP?
As Cast is the default condition — default supply form for valve trim, seat rings and cast wear parts; maximum carbide content, lowest ductility. HIP: choose for near-net-shape parts needing uniform fine carbides, higher strength and better toughness than cast Stellite 6. Yield strength is 541 MPa in As Cast versus 680 MPa in HIP.
How much does Stellite 6 cost?
Stellite 6 is a specialty-cost cobalt-chrome alloy ($$$$$), pricier than about 99% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- Stellite 6 Alloy Technical Data — Kennametal Stellite (Deloro) (2021)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (Cobalt alloys) — ASM International (1990)
- AWS A5.21 / A5.13 — Bare and covered hardfacing electrodes (ERCCoCr-A, RCoCr-A) — AWS (2021)
- ASTM A560 / UNS R30006 cobalt-chromium-tungsten alloy castings — ASTM (2019)
- ASM Handbook Vol.19 — Fatigue and Fracture (hardfacing alloys) — ASM International (1996)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.