VK15 KS
Grade
GOST VK15 (ВК15) · GB YG15
KS = coarse grain (4–8 µm WC), ВК15-КС
Maximum toughness and thermal conductivity variant for rock drilling, mining picks and hot-shock service where fracture, not wear, is the failure mode.
Values for the KS condition
Other VK15 tempers and conditions
VK15 is listed in 3 conditions; see the grade overview at VK15.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
KSThis page Coarse grain (4–8 µm WC), ВК15-КС | Maximum toughness and thermal conductivity variant for rock drilling, mining picks and hot-shock service where fracture, not wear, is the failure mode. | — | 1,150 | 0.25 | 950 HV | 80 W/m·K |
Thermomechanically controlled processed | Pick when higher hardness and edge retention are needed on impact-loaded tools, e.g. wire-drawing dies and cold-heading punches for harder wire. | — | 1,250 | 0.2 | 1,200 HV | 62 W/m·K |
Ultrafine grain with grain-growth inhibitors (0.5–0.8 µm WC), ВК15-ОМ | Highest hardness plus high strength combination — for precision punches, micro-dies and interrupted cutting of hard-to-machine alloys. | — | 1,400 | 0.18 | 1,300 HV | 55 W/m·K |
What is VK15 KS?
VK15 KS is VK15 in the KS grade — maximum toughness and thermal conductivity variant for rock drilling, mining picks and hot-shock service where fracture, not wear, is the failure mode. VK15 KS has a tensile strength of 1,150 MPa (167 ksi), stronger than 90% of ceramic grades. Elongation at break is 0.25% and the elastic modulus is 510 GPa (74 Msi). VK15 KS has a density of 14 g/cm³ (0.506 lb/in³), heavier than 88% of ceramic grades. It melts at 1,320°C (2,408 °F).
Advantages
- Tough — resists crack growth — 19 MPa·√m (17.3 ksi·√in), better than 100% of ceramic grades
- Ductile — tolerates forming and impact — 0.25%, better than 85% of ceramic grades
- Stiff — 510 GPa (74 Msi), better than 78% of ceramic grades
- Conducts heat well — 80 W/m·K (46.2 BTU/hr·ft·°F), better than 77% of ceramic grades
Limitations
- High embodied carbon — 30 kg CO₂/kg, worse than 91% of ceramic grades
- Heavy — 14 g/cm³ (0.506 lb/in³), worse than 88% of ceramic grades
- Needs corrosion protection — 47/100, worse than 85% of ceramic grades
VK15 KS properties
Typical room-temperature values for VK15 KS; 14 are specific to this condition. Other listed values are VK15 reference data and may not represent this condition. Bars are the position among ceramic grades.
Physical3
VK15 KS has a density of 14 g/cm³ (0.506 lb/in³), heavier than 88% of ceramic grades. It melts at 1,320°C (2,408 °F).
Mechanical12
VK15 KS has a tensile strength of 1,150 MPa (167 ksi), stronger than 90% of ceramic grades. Elongation at break is 0.25% and the elastic modulus is 510 GPa (74 Msi).
Thermal5
VK15 KS is rated for continuous service to 600°C (1,112 °F). It conducts heat at 80 W/m·K (46.2 BTU/hr·ft·°F), better than 77% of ceramic grades. Thermal expansion is 5.8 µm/m·K (3.22 µin/in·°F).
Electrical1
VK15 KS has an electrical resistivity of 1.8×10⁻⁷ Ω·m.
Chemical & Environmental2
Corrosion resistance is fair (47/100), worse than 85% of ceramic grades.
Sustainability4
Producing a kilogram of VK15 KS takes about 400 MJ of energy and emits 30 kg of CO₂ — more than 88% of ceramic grades. Typical recycled content is 30%.
Manufacturability3
VK15 KS's machinability is not recommended (7/100, better than 63% of ceramic grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with VK15 KS
Is VK15 easy to machine?
Only diamond grinding, wire/sinker EDM, laser or ultrasonic machining after sintering; green (pre-sintered) blanks can be turned with carbide tools before final sinter.
Can VK15 be welded?
Not fusion weldable — joined to steel bodies by silver/copper brazing (Ag-Cu-Zn or Cu-Mn) or by shrink fitting; slow heating and cooling to avoid thermal cracking.
Can VK15 be formed, bent or molded?
Formed by powder pressing, extrusion or injection moulding of WC-Co feedstock followed by vacuum/sinter-HIP at ~1400–1450 °C with ~18–20% linear shrinkage.
What surface finishes work on VK15?
Diamond lapping and polishing gives mirror surfaces; PVD TiN/TiAlCN coatings possible but limited by the low binder-phase hot hardness — avoid acid pickling which leaches cobalt.
VK15 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 | 14 – 16 | 15 |
| Ctotal carbon balanced to avoid eta phase / free graphite | — | — |
| other carbides (TaC/NbC/VC/Cr3C2)only in M/OM grain-refined variants as growth inhibitors | 0 – 0.5 | 0.2 |
| WCtungsten carbide hard phase, balance | balance | — |
VK15 KS — frequently asked
What is VK15 KS used for?
VK15 KS is typically used for heavy cold-work dies, structural wear plates and mining tools. In short: toughest common BK grade; high-cobalt impact carbide; shock service over abrasion.
What is the tensile strength of VK15 KS?
VK15 KS has a typical tensile strength of 1,150 MPa (167 ksi) — stronger than 90% of ceramic grades. Strength varies by condition: see the 3 listed tempers.
Is VK15 KS easy to machine?
Not especially — machinability is rated not recommended (7/100, better than 63% of ceramic grades). Only diamond grinding, wire/sinker EDM, laser or ultrasonic machining after sintering; green (pre-sintered) blanks can be turned with carbide tools before final sinter.
Can VK15 KS be welded?
Not fusion weldable — joined to steel bodies by silver/copper brazing (Ag-Cu-Zn or Cu-Mn) or by shrink fitting; slow heating and cooling to avoid thermal cracking.
What surface finishes work on VK15 KS?
Diamond lapping and polishing gives mirror surfaces; PVD TiN/TiAlCN coatings possible but limited by the low binder-phase hot hardness — avoid acid pickling which leaches cobalt.
Can VK15 KS be formed, bent or molded?
Formed by powder pressing, extrusion or injection moulding of WC-Co feedstock followed by vacuum/sinter-HIP at ~1400–1450 °C with ~18–20% linear shrinkage.
What is the maximum service temperature of VK15 KS?
VK15 KS 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
- GOST 3882-74 Сплавы твердые спеченные. Марки — Gosstandart (1974)
- ASM Handbook Vol. 2 — Properties of Cemented Carbides — ASM International (1990)
- ISO 4505 Hardmetals — Metallographic determination of porosity — ISO (1978)
- Cemented carbide grade property tables (WC-Co series) — Sandvik Hard Materials (2020)
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.