Tungsten Alloy WC-6Co
WC-6Co (GB YG6, ISO K20) is a straight tungsten-carbide/cobalt cemented carbide with about 6 wt% cobalt binder, giving hardness near 1550 HV, extreme compressive strength, stiffness of E ≈ 630 GPa and strength around 1300 MPa at 14.9 g/cm³.
Reference datasheet — WC-6Co 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 Sintered condition
WC-6Co tempers and conditions
WC-6Co is supplied in 4 conditions, soft to hard. Sintered is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
WC 2.5–5 µm (YG6C / K30-type) | Use for mining/rock drilling buttons, interrupted cuts and impact wear parts where thermal-shock and toughness beat peak hardness. | 1,250 | 0 | 77 HRC | 9.6 % IACS | |
SinteredDefault vacuum/pressure sintered, medium grain (~1–2 µm WC) | Standard as-supplied condition for YG6/K20 blanks, rods, strips and wear parts — balanced hardness and toughness. | 1,300 | 0 | 78 HRC | 8.6 % IACS | |
Hot isostatic pressed | Choose when residual porosity must be eliminated: highest transverse rupture strength and fatigue life for impact tooling, dies and long inserts. | 1,450 | 0 | 79 HRC | 8.8 % IACS | |
WC 0.5–0.8 µm with VC/Cr3C2 inhibitors (YG6X) | Pick for sharp-edge micro tools, PCB drills, hard non-ferrous and finishing cuts where edge strength and hardness matter more than toughness. | 1,500 | 0 | 1,750 HV | 7.8 % IACS |
Supply forms, finishes and certifications
Ways WC-6Co is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
Ground | Precision diamond-ground blanks/rods | Surface finish |
What is WC-6Co?
WC-6Co (GB YG6, ISO K20) is a straight tungsten-carbide/cobalt cemented carbide with about 6 wt% cobalt binder, giving hardness near 1550 HV, extreme compressive strength, stiffness of E ≈ 630 GPa and strength around 1300 MPa at 14.9 g/cm³. It is the workhorse grade for cast-iron and non-ferrous turning and milling inserts, wear parts, dies, nozzles, punches and blades. Limits are brittleness (essentially zero ductility, K_IC ≈ 10 MPa·√m), crater and diffusion wear when machining steel uncoated, acid attack on the cobalt binder, and oxidation above roughly 500-600 °C; it can only be shaped by grinding, EDM or laser. WC-6Co has a density of 14.9 g/cm³ (0.538 lb/in³), lighter than 86% of tungsten alloy grades. It melts at 1,320°C (2,408 °F). WC-6Co has a tensile strength of 1,300 MPa (189 ksi), stronger than 71% of tungsten alloy grades. Elongation at break is 0% and the elastic modulus is 630 GPa (91.4 Msi).
What is WC-6Co used for?
- Turning and milling inserts for cast iron
- Non-ferrous cutting inserts
- Wear parts and bushings
- Cold-forming dies
- Spray and blast nozzles
- Punches
- Cutting blades
Advantages
- Stiff — 630 GPa (91.4 Msi), better than 100% of tungsten alloy grades
- Polishes to a fine finish — 92/100, better than 100% of tungsten alloy grades
- Low embodied carbon — 18 kg CO₂/kg, better than 95% of tungsten alloy grades
- Lightweight — 14.9 g/cm³ (0.538 lb/in³), better than 86% of tungsten alloy grades
Limitations
- Limited ductility — 0%, worse than 97% of tungsten alloy grades
- Poor heat conductor — 80 W/m·K (46.2 BTU/hr·ft·°F), worse than 90% of tungsten alloy grades
- Low fracture toughness — 10 MPa·√m (9.1 ksi·√in), worse than 83% of tungsten alloy grades
- Low electrical conductivity — 8.6 % IACS, worse than 83% of tungsten alloy grades
WC-6Co properties
Typical room-temperature values for WC-6Co-Sintered; bars are the position among tungsten alloy grades.
Physical2
WC-6Co has a density of 14.9 g/cm³ (0.538 lb/in³), lighter than 86% of tungsten alloy grades. It melts at 1,320°C (2,408 °F).
Mechanical14
WC-6Co has a tensile strength of 1,300 MPa (189 ksi), stronger than 71% of tungsten alloy grades. Elongation at break is 0% and the elastic modulus is 630 GPa (91.4 Msi).
Thermal5
WC-6Co is rated for continuous service to 500°C (932 °F). It conducts heat at 80 W/m·K (46.2 BTU/hr·ft·°F), worse than 90% of tungsten alloy grades. Thermal expansion is 5.2 µm/m·K (2.89 µin/in·°F).
Electrical3
WC-6Co conducts electricity at 8.6 % IACS, worse than 83% of tungsten alloy grades.
Chemical & Environmental3
Corrosion resistance is fair (50/100), worse than 69% of tungsten alloy grades.
Sustainability4
Producing a kilogram of WC-6Co takes about 250 MJ of energy and emits 18 kg of CO₂ — less than 95% of tungsten alloy grades. Typical recycled content is 35%.
Manufacturability7
WC-6Co's machinability is not recommended (3/100, worse than 95% of tungsten alloy grades); weldability not recommended (10/100); formability not recommended (1/100).
Common Calculations4
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 tungsten alloy family
Yield strength against density for every tungsten alloy grade FabDigit runs. WC-6Co is highlighted; hover a dot for its name, or open the interactive family chart.
Working with WC-6Co
Is WC-6Co easy to machine?
Not machinable by conventional cutting — shape by diamond-wheel grinding, wire/sinker EDM, laser or ultrasonic; grind wet with rigid setups to avoid thermal cracking.
Can WC-6Co be welded?
Cannot be fusion welded; join by vacuum or induction brazing with Ag-Cu-Zn (BAg) or Cu-Mn filler using a soft interlayer to absorb CTE mismatch, or by shrink-fit/adhesive.
Can WC-6Co be formed, bent or molded?
Net shape is made by pressing WC/Co powder (uniaxial, CIP or extrusion/injection) and vacuum or Sinter-HIP sintering with ~18–20 % linear shrinkage; green/pre-sintered blanks can be soft-machined before final sintering.
WC-6Co 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 |
|---|---|---|
| Cobinder phase | 5.5 – 6.5 | 6 |
| Ccombined carbon in WC; free C and eta-phase must be absent | 5.5 – 5.8 | 5.7 |
| VC+Cr3C2grain-growth inhibitors, fine-grain variants only | 0 – 1 | 0.3 |
| TaC/NbCoptional minor addition | 0 – 0.5 | 0 |
| WCbalance, ~94 wt% | balance |
What surface finishes work on WC-6Co?
Diamond lapping/polishing gives mirror surfaces; PVD TiAlN or CVD TiCN-Al2O3 coatings, micro-blasting and edge honing are standard; avoid acid pickling that leaches the cobalt binder.
How much does WC-6Co cost?
WC-6Co is a specialty-cost tungsten alloy ($$$$$), pricier than about 99% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
WC-6Co — frequently asked
What is WC-6Co used for?
WC-6Co is typically used for turning and milling inserts for cast iron, non-ferrous cutting inserts, wear parts and bushings, cold-forming dies, spray and blast nozzles and punches. In short: premium wear cemented carbide.
What is the tensile strength of WC-6Co?
WC-6Co has a typical tensile strength of 1,300 MPa (189 ksi) — stronger than 71% of tungsten alloy grades. Strength varies by condition: see the 4 listed tempers.
Is WC-6Co easy to machine?
Not especially — machinability is rated not recommended (3/100, worse than 95% of tungsten alloy grades). Not machinable by conventional cutting — shape by diamond-wheel grinding, wire/sinker EDM, laser or ultrasonic; grind wet with rigid setups to avoid thermal cracking.
Can WC-6Co be welded?
Not readily — weldability is rated not recommended (10/100). Cannot be fusion welded; join by vacuum or induction brazing with Ag-Cu-Zn (BAg) or Cu-Mn filler using a soft interlayer to absorb CTE mismatch, or by shrink-fit/adhesive.
What surface finishes work on WC-6Co?
Diamond lapping/polishing gives mirror surfaces; PVD TiAlN or CVD TiCN-Al2O3 coatings, micro-blasting and edge honing are standard; avoid acid pickling that leaches the cobalt binder.
Can WC-6Co be formed, bent or molded?
Net shape is made by pressing WC/Co powder (uniaxial, CIP or extrusion/injection) and vacuum or Sinter-HIP sintering with ~18–20 % linear shrinkage; green/pre-sintered blanks can be soft-machined before final sintering.
What is the maximum service temperature of WC-6Co?
WC-6Co is rated for continuous use to about 500°C (932 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does WC-6Co cost?
WC-6Co is a specialty-cost tungsten alloy ($$$$$), 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
- ISO 513 Classification and application of hard cutting materials — ISO (2012)
- ISO 3878 Hardmetals — Vickers hardness test / ISO 3369 density / ISO 28079 Palmqvist toughness — ISO (2019)
- ASM Handbook Vol. 2 & Engineered Materials Handbook — Cemented Carbides — ASM International (1990)
- Cemented carbide grade data (WC-6Co, K20 class) — Sandvik Hard Materials / Kennametal / (2023)
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.