C2 CG
Grade
GB YG6 · ISO K20
CG = coarse grain (3–6 µm WC), 6 % Co
Choose for interrupted cuts, rock/asphalt tools and thermally shocked wear parts where toughness and heat conduction beat peak hardness.
Values for the CG condition
Other C2 tempers and conditions
C2 is listed in 3 conditions; see the grade overview at C2.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
CGThis page Coarse grain (3–6 µm WC), 6 % Co | Choose for interrupted cuts, rock/asphalt tools and thermally shocked wear parts where toughness and heat conduction beat peak hardness. | — | 1,100 | 0 | 1,350 HV | 110 W/m·K |
MGDefault Medium grain (1–3 µm WC), 6 % Co, as-sintered/HIP | Standard C2/K20/YG6 balance of hardness and toughness — default for cast iron and non-ferrous turning, milling and general wear parts. | — | 1,200 | 0 | 1,580 HV | 85 W/m·K |
Submicron / fine grain (0.5–0.8 µm WC), 6 % Co | Pick when a keen, chip-free cutting edge is needed — micro-drills, end mills, PCB routers, punches and fine-blanking dies. | — | 1,450 | 0 | 1,750 HV | 70 W/m·K |
What is C2 CG?
C2 CG is C2 in the CG grade — choose for interrupted cuts, rock/asphalt tools and thermally shocked wear parts where toughness and heat conduction beat peak hardness. C2 CG has a tensile strength of 1,100 MPa (160 ksi), stronger than 88% of ceramic grades. Elongation at break is 0% and the elastic modulus is 620 GPa (89.9 Msi). C2 CG has a density of 14.9 g/cm³ (0.538 lb/in³), heavier than 96% of ceramic grades. It melts at 1,320°C (2,408 °F). MG is the default condition FabDigit quotes; CG is available on request or by drawing note.
Advantages
- Tough — resists crack growth — 12.5 MPa·√m (11.4 ksi·√in), better than 94% of ceramic grades
- Stiff — 620 GPa (89.9 Msi), better than 93% of ceramic grades
- Conducts heat well — 110 W/m·K (63.6 BTU/hr·ft·°F), better than 86% of ceramic grades
Limitations
- Heavy — 14.9 g/cm³ (0.538 lb/in³), worse than 96% of ceramic grades
- Needs corrosion protection — 45/100, worse than 90% of ceramic grades
- High embodied carbon — 28 kg CO₂/kg, worse than 84% of ceramic grades
C2 CG properties
Typical room-temperature values for C2 CG; 14 are specific to this condition. Other listed values are C2 reference data and may not represent this condition. Bars are the position among ceramic grades.
Physical3
C2 CG has a density of 14.9 g/cm³ (0.538 lb/in³), heavier than 96% of ceramic grades. It melts at 1,320°C (2,408 °F).
Mechanical13
C2 CG has a tensile strength of 1,100 MPa (160 ksi), stronger than 88% of ceramic grades. Elongation at break is 0% and the elastic modulus is 620 GPa (89.9 Msi).
Thermal5
C2 CG is rated for continuous service to 600°C (1,112 °F). It conducts heat at 110 W/m·K (63.6 BTU/hr·ft·°F), better than 86% of ceramic grades. Thermal expansion is 5.2 µm/m·K (2.89 µin/in·°F).
Electrical2
C2 CG has an electrical resistivity of 1.8×10⁻⁷ Ω·m.
Chemical & Environmental2
Corrosion resistance is fair (45/100), worse than 90% of ceramic grades.
Sustainability4
Producing a kilogram of C2 CG takes about 420 MJ of energy and emits 28 kg of CO₂ — more than 93% of ceramic grades. Typical recycled content is 30%.
Manufacturability3
C2 CG's machinability is not recommended (6/100, better than 61% of ceramic grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with C2 CG
Is C2 easy to machine?
Not conventionally machinable — shape by pressing/extruding the green body, then finish by diamond grinding, wire/sinker EDM (it is electrically conductive), laser or ultrasonic machining.
Can C2 be welded?
Not fusion-weldable; joined by vacuum or induction brazing with Ag-Cu-Zn or Cu-Mn filler onto steel bodies, or by shrink-fitting/adhesive bonding, with a slow controlled cool to limit CTE-mismatch cracking.
Can C2 be formed, bent or molded?
Powder metallurgy only: WC+Co milled, spray-dried, uniaxially/isostatically pressed or extruded, dewaxed and liquid-phase sintered (sinter-HIP) at ~1400–1450 °C with ~18–20 % linear shrinkage.
What surface finishes work on C2?
Diamond wheels and laps give mirror finishes; PVD TiN/TiAlN or CVD coatings are standard for cutting tools; can be electroplated after suitable activation, but avoid acidic baths that leach the cobalt binder.
C2 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 |
|---|---|---|
| Cometallic binder phase | 5.5 – 6.5 | 6 |
| TaC+NbCoptional grain-growth inhibitor / additive | 0 – 0.5 | 0.2 |
| Cr3C2+VCgrain refiner, used mainly in the fine-grain variant | 0 – 0.6 | 0 |
| WCbalance; C content held near stoichiometric 6.13 % to avoid eta phase or free graphite | balance | — |
C2 CG — frequently asked
What is C2 CG used for?
C2 CG is typically used for general cast iron turning/milling, non-ferrous machining and brazed tool tips. In short: general-purpose K-group carbide; balanced hardness and toughness; standard brazed-tip grade.
What is the tensile strength of C2 CG?
C2 CG has a typical tensile strength of 1,100 MPa (160 ksi) — stronger than 88% of ceramic grades. Strength varies by condition: see the 3 listed tempers.
Is C2 CG easy to machine?
Not especially — machinability is rated not recommended (6/100, better than 61% of ceramic grades). Not conventionally machinable — shape by pressing/extruding the green body, then finish by diamond grinding, wire/sinker EDM (it is electrically conductive), laser or ultrasonic machining.
Can C2 CG be welded?
Not fusion-weldable; joined by vacuum or induction brazing with Ag-Cu-Zn or Cu-Mn filler onto steel bodies, or by shrink-fitting/adhesive bonding, with a slow controlled cool to limit CTE-mismatch cracking.
What surface finishes work on C2 CG?
Diamond wheels and laps give mirror finishes; PVD TiN/TiAlN or CVD coatings are standard for cutting tools; can be electroplated after suitable activation, but avoid acidic baths that leach the cobalt binder.
Can C2 CG be formed, bent or molded?
Powder metallurgy only: WC+Co milled, spray-dried, uniaxially/isostatically pressed or extruded, dewaxed and liquid-phase sintered (sinter-HIP) at ~1400–1450 °C with ~18–20 % linear shrinkage.
What is the maximum service temperature of C2 CG?
C2 CG is rated for continuous use to about 600°C (1,112 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ISO 513 — Classification and application of hard cutting materials (K20) — ISO (2012)
- ASTM B276 / B406 — Apparent porosity and transverse rupture strength of cemented carbides — ASTM (2020)
- ASM Engineered Materials Handbook Vol. 4 — Ceramics and Glasses / Cemented Carbides — ASM International (1991)
- Cemented carbide grade property tables (WC-6Co) — Kennametal / Sandvik Hard Materials / Ceratizit / (2023)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.