FabDigitFabDigit

C4 UF

Grade

GB YG3 · ISO K01

UF = ultrafine/submicron WC-3Co (0.4–0.8 µm), YG3X

Pick when maximum hardness and a keen, chip-free edge are needed — micro-tools, PCB drills, precision dies and slitters.

High cost $$$$
Request a quote in C4 UFC4 overview

Values for the UF condition

Other C4 tempers and conditions

C4 is listed in 2 conditions; see the grade overview at C4.

Compare all 2 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
FGDefault
Fine grain WC-3Co (1.0–1.5 µm), as-sintered/ground
Standard C4/K01 straight carbide for finishing cast iron and non-ferrous alloys and for general wear parts.—1,20001,850 HV100 W/m·K
UFThis page
Ultrafine/submicron WC-3Co (0.4–0.8 µm), YG3X
Pick when maximum hardness and a keen, chip-free edge are needed — micro-tools, PCB drills, precision dies and slitters.———2,050 HV85 W/m·K

What is C4 UF?

C4 UF is C4 in the UF grade — pick when maximum hardness and a keen, chip-free edge are needed — micro-tools, PCB drills, precision dies and slitters. C4 UF has a tensile strength of 1,200 MPa (174 ksi), stronger than 94% of ceramic grades. Elongation at break is 0% and the elastic modulus is 670 GPa (97.2 Msi). C4 UF has a density of 15.15 g/cm³ (0.547 lb/in³), heavier than 99% of ceramic grades. It melts at 1,320°C (2,408 °F). FG is the default condition FabDigit quotes; UF is available on request or by drawing note.

Advantages

  • Stiff — 670 GPa (97.2 Msi), better than 99% of ceramic grades
  • Polishes to a fine finish — 96/100, better than 99% of ceramic grades
  • Tough — resists crack growth — 8.5 MPa·√m (7.74 ksi·√in), better than 79% of ceramic grades
  • Conducts heat well — 85 W/m·K (49.1 BTU/hr·ft·°F), better than 79% of ceramic grades

Limitations

  • Heavy — 15.15 g/cm³ (0.547 lb/in³), worse than 99% of ceramic grades
  • High embodied carbon — 30 kg CO₂/kg, worse than 91% of ceramic grades
  • Needs corrosion protection — 45/100, worse than 90% of ceramic grades

C4 UF properties

Typical room-temperature values for C4 UF; 10 are specific to this condition. Other listed values are C4 reference data and may not represent this condition. Bars are the position among ceramic grades.

Physical3

C4 UF has a density of 15.15 g/cm³ (0.547 lb/in³), heavier than 99% of ceramic grades. It melts at 1,320°C (2,408 °F).

Density15.15 g/cm³0.55 lb/in³
Melting Point (Solidus)1,320°C2,408 °F
Porosity0.02%

Mechanical13

C4 UF has a tensile strength of 1,200 MPa (174 ksi), stronger than 94% of ceramic grades. Elongation at break is 0% and the elastic modulus is 670 GPa (97.2 Msi).

Elastic (Young's) Modulus670 GPa97.2 Msi
Shear Modulus275 GPa39.9 Msi
Bulk Modulus382 GPa55.4 Msi
Poisson's Ratio0.21
Tensile Strength (Ultimate)1,200 MPa174 ksi
Elongation at Break0%
Compressive Strength7,200 MPa1,044 ksi
Flexural Strength2,200 MPa319 ksi
Shear Strength1,200 MPa174 ksi
Fracture Toughness (K_IC)8.5 MPa·√m7.7 ksi·√in
Hardness, Vickers2,050 HV
Hardness, Knoop1,800 HK
Hardness, Mohs9

Thermal5

C4 UF is rated for continuous service to 600°C (1,112 °F). It conducts heat at 85 W/m·K (49.1 BTU/hr·ft·°F), better than 79% of ceramic grades. Thermal expansion is 4.5 µm/m·K (2.5 µin/in·°F).

Thermal Conductivity85 W/m·K49.1 BTU/hr·ft·°F
Specific Heat Capacity210 J/kg·K0.05 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)4.5 µm/m·K2.5 µin/in·°F
Max Service Temperature (continuous)600°C1,112 °F
Min Service Temperature-196°C-321 °F

Electrical2

C4 UF has an electrical resistivity of 1.9×10⁻⁷ Ω·m.

Electrical Resistivity1.9×10⁻⁷ Ω·m7.48 µΩ·in
Volume Resistivity1.9×10⁻⁵ Ω·cm

Chemical & Environmental2

Corrosion resistance is fair (45/100), worse than 90% of ceramic grades.

Corrosion ResistanceFair45/100
Chemical Resistance SummaryWC skeleton is chemically very stable; the cobalt binder is leached by mineral acids (HCl, H2SO4, HNO3), by strong alkalis at temperature and by acidic coolants, causing surface embrittlement. Good against neutral coolants, oils, solvents and molten non-ferrous metals; oxidises rapidly in air above ~600 °C.

Sustainability4

Producing a kilogram of C4 UF takes about 400 MJ of energy and emits 30 kg of CO₂ — more than 88% of ceramic grades. Typical recycled content is 30%.

Embodied Energy (primary production)400 MJ/kg171,969 BTU/lb
Embodied Carbon (primary production)30 kg CO₂/kg
Embodied Water300 L/kg35.9 gal/lb
Typical Recycled Content30%

Manufacturability3

C4 UF's machinability is not recommended (3/100, worse than 95% of ceramic grades).

MachinabilityNot recommended3/100
PolishabilityExcellent96/100
Sintering / Firing Temperature1,420°C2,588 °F

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with C4 UF

Is C4 easy to machine?

Only diamond grinding, wire/sinker EDM, laser or ultrasonic machining — never conventional cutting; grind wet with generous coolant to avoid thermal cracks.

Can C4 be welded?

Not fusion weldable; join by vacuum or induction brazing with Ag-Cu-(Ti/Ni) filler below ~900 °C, using a shim to absorb CTE mismatch with steel.

Can C4 be formed, bent or molded?

Net-shape by pressing or extruding WC-Co powder with binder then vacuum/sinter-HIP at ~1420 °C with ~18–22 % linear shrinkage; no plastic forming after sintering.

What surface finishes work on C4?

Diamond lapping/polishing to mirror finish; PVD TiN/TiAlN or CVD coatings and micro-blast edge honing are standard for cutting tools.

C4 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.

ElementSpec limit (wt %)Nominal
Cobinder phase; defines toughness/hardness balance2.5 – 43
TiC+TaC+NbCstraight grade — cubic carbides only as trace grain-growth inhibitor level0 – 0.50
Cr3C2/VCgrain-growth inhibitor, mainly in the ultrafine variant0 – 0.80.4
WCbalance, ~96 wt %; total C ≈ 5.9 %balance—

C4 UF — frequently asked

What is C4 UF used for?

C4 UF is typically used for precision finishing, wire drawing dies and fine boring. In short: hardest US straight carbide; stiffest grade, 665 GPa; light-cut finishing only.

What is the tensile strength of C4 UF?

C4 UF has a typical tensile strength of 1,200 MPa (174 ksi) — stronger than 94% of ceramic grades. Strength varies by condition: see the 2 listed tempers.

Is C4 UF easy to machine?

Not especially — machinability is rated not recommended (3/100, worse than 95% of ceramic grades). Only diamond grinding, wire/sinker EDM, laser or ultrasonic machining — never conventional cutting; grind wet with generous coolant to avoid thermal cracks.

Can C4 UF be welded?

Not fusion weldable; join by vacuum or induction brazing with Ag-Cu-(Ti/Ni) filler below ~900 °C, using a shim to absorb CTE mismatch with steel.

What surface finishes work on C4 UF?

Diamond lapping/polishing to mirror finish; PVD TiN/TiAlN or CVD coatings and micro-blast edge honing are standard for cutting tools.

Can C4 UF be formed, bent or molded?

Net-shape by pressing or extruding WC-Co powder with binder then vacuum/sinter-HIP at ~1420 °C with ~18–22 % linear shrinkage; no plastic forming after sintering.

What is the maximum service temperature of C4 UF?

C4 UF 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

  1. ISO 513 — Classification of hard cutting materials (K01 application group) — ISO (2012)
  2. ASTM B276 / B406 — Apparent porosity and transverse rupture strength of cemented carbides — ASTM (2020)
  3. ASM Handbook Vol. 2 — Properties of Cemented Carbides — ASM International (1990)
  4. Straight-grade WC-Co hardmetal property tables — Kennametal / Sandvik Hard Materials / Zhuzhou Cemented Carbide (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.