C8
GB YT30 · ISO P10
C8 is the hardest P-group cemented carbide in the US application classification, a WC-TiC-Co composition with high TiC content and low cobalt, known as YT30 in CIS practice.
Reference datasheet — C8 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 UC condition
C8 tempers and conditions
C8 is supplied in 2 conditions, soft to hard. UC is the default FabDigit quotes; the values on this page are for it.
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
UCDefault Uncoated C8 | Use the general-purpose uncoated C8/P10 finishing substrate for high-speed finish turning, fine boring and form tools on steel. | 1,650 HV | 30 W/m·K | |||
GB grade WC–30TiC–4Co, highest hardness / lowest toughness | Pick the WC–30TiC–4Co composition for the hardest, highest-speed finish turning and boring of steel, but restrict it to light continuous cuts and never interrupted cutting. | 1,780 HV | 21 W/m·K |
Supply forms, finishes and certifications
Ways C8 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
CVD | C8/P10 substrate with TiCN–Al₂O₃–TiN CVD coating | Coating |
What is C8?
C8 is the hardest P-group cemented carbide in the US application classification, a WC-TiC-Co composition with high TiC content and low cobalt, known as YT30 in CIS practice. It is chosen for precision finishing and very light, high-speed cuts on steel, where hardness and crater resistance dominate over toughness; it is supplied as uncoated (UC) and CVD-coated inserts and blanks. Density is 10.4 g/cm³, elastic modulus 520 GPa, thermal conductivity 30 W/m·K and maximum service temperature about 900 °C. The low binder content makes it brittle and unsuitable for interrupted or heavy cuts — step down to C7 where more edge security is needed. C8 has a density of 10.4 g/cm³ (0.376 lb/in³), heavier than 78% of ceramic grades. It melts at 1,320°C (2,408 °F). C8 has a tensile strength of 900 MPa (131 ksi), stronger than 83% of ceramic grades. Elongation at break is 0% and the elastic modulus is 520 GPa (75.4 Msi).
What is C8 used for?
- precision steel finishing
- fine boring of steel
- high-speed light turning
Advantages
- Polishes to a fine finish — 92/100, better than 89% of ceramic grades
- Stiff — 520 GPa (75.4 Msi), better than 81% of ceramic grades
Limitations
- Heavy — 10.4 g/cm³ (0.376 lb/in³), worse than 78% of ceramic grades
- Needs corrosion protection — 55/100, worse than 77% of ceramic grades
C8 properties
Typical room-temperature values for C8-UC; bars are the position among ceramic grades.
Physical3
C8 has a density of 10.4 g/cm³ (0.376 lb/in³), heavier than 78% of ceramic grades. It melts at 1,320°C (2,408 °F).
Mechanical13
C8 has a tensile strength of 900 MPa (131 ksi), stronger than 83% of ceramic grades. Elongation at break is 0% and the elastic modulus is 520 GPa (75.4 Msi).
Thermal5
C8 is rated for continuous service to 900°C (1,652 °F). It conducts heat at 30 W/m·K (17.3 BTU/hr·ft·°F), better than 60% of ceramic grades. Thermal expansion is 6.5 µm/m·K (3.61 µin/in·°F).
Electrical2
C8 has an electrical resistivity of 5×10⁻⁷ Ω·m.
Chemical & Environmental2
Corrosion resistance is good (55/100), worse than 77% of ceramic grades.
Sustainability4
Producing a kilogram of C8 takes about 90 MJ of energy and emits 6.5 kg of CO₂ — less than 62% of ceramic grades. Typical recycled content is 30%.
Manufacturability3
C8's machinability is not recommended (5/100, worse than 59% of ceramic grades).
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 ceramic family
Yield strength against density for every ceramic grade FabDigit runs. C8 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C8
Is C8 easy to machine?
Shape only by diamond wheel grinding, wire EDM or laser; conventional cutting tools cannot be used, and grinding must be flooded with coolant to prevent thermal cracking.
Can C8 be welded?
Not fusion weldable; braze to steel bodies with silver fillers (BAg-1/BAg-3) in vacuum or by induction, using preheat and slow cooling to manage the CTE mismatch.
Can C8 be formed, bent or molded?
Near-net-shape powder metallurgy: die pressing, extrusion or powder injection moulding followed by liquid-phase sintering or sinter-HIP at 1400–1500 °C; allow for about 18–20 % sintering shrinkage in the tooling.
C8 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; C8 uses lower limit for higher hardness | 4 – 7 | 5.5 |
| TiCresists crater wear; YT30 contains 30 % | 8 – 30 | 14 |
| TaC+NbCrefines grain, improves hot strength | 0 – 8 | 4 |
| WCmain hard phase | balance |
What surface finishes work on C8?
Diamond lapping and polishing produce a mirror cutting edge; CVD (TiCN-Al₂O₃-TiN) or PVD (TiAlN) coatings are common, with edge honing carried out before coating.
Equivalent designations
Standards and trade names that resolve to C8 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ISO
- P10
- GB (China)
- YT30
How much does C8 cost?
C8 is a high-cost ceramic ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
C8 — frequently asked
What is C8 used for?
C8 is typically used for precision steel finishing, fine boring of steel and high-speed light turning. In short: hardest P-group carbide; precision finishing only; low cobalt, low toughness.
What is the tensile strength of C8?
C8 has a typical tensile strength of 900 MPa (131 ksi) — stronger than 83% of ceramic grades. Strength varies by condition: see the 2 listed tempers.
Is C8 easy to machine?
Not especially — machinability is rated not recommended (5/100, worse than 59% of ceramic grades). Shape only by diamond wheel grinding, wire EDM or laser; conventional cutting tools cannot be used, and grinding must be flooded with coolant to prevent thermal cracking.
Can C8 be welded?
Not fusion weldable; braze to steel bodies with silver fillers (BAg-1/BAg-3) in vacuum or by induction, using preheat and slow cooling to manage the CTE mismatch.
What surface finishes work on C8?
Diamond lapping and polishing produce a mirror cutting edge; CVD (TiCN-Al₂O₃-TiN) or PVD (TiAlN) coatings are common, with edge honing carried out before coating.
Can C8 be formed, bent or molded?
Near-net-shape powder metallurgy: die pressing, extrusion or powder injection moulding followed by liquid-phase sintering or sinter-HIP at 1400–1500 °C; allow for about 18–20 % sintering shrinkage in the tooling.
What is the maximum service temperature of C8?
C8 is rated for continuous use to about 900°C (1,652 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does C8 cost?
C8 is a high-cost ceramic ($$$$), pricier than about 78% 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
- ASTM B777 / C-grade classification for cemented carbides — ASTM (2015)
- ISO 513 Classification and application of hard cutting materials — ISO (2012)
- ASM Handbook Vol.16 Machining — Cemented Carbides — ASM International (1989)
- ASM Handbook Vol.7 Powder Metallurgy — Cemented Carbide Processing — ASM International (2015)
- ( / Kennametal / Sandvik Coromant) (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.