10 comparative cutting test reports recorded on customer machines. In every test the tool geometry, machine, coolant and cutting data stayed the same — only the insert grade changed, from the reference cermet grade to KOVES KT20. Results are published as recorded, including the 5 tests where tool life came out equal.
Each test below is one table, in the same form our engineers fill in on the shop floor: workpiece and operation, the two tools compared side by side, the cutting conditions both tools ran, and the recorded tool life in parts per edge. 5 of 10 tests show a tool-life gain; the rest reached parity and were stopped before the wear limit — we report both.





Comparative cutting test on 45 carbon steel (C45 / AISI 1045): KOVES KT20 TNMG160408 (HQ) against the reference cermet grade the customer used before Tool life 1200 vs 1000 parts per edge at identical cutting data (1.20× longer edge life). Operation: bore + facing, continuous cut, cnc horizontal lathe.
| Item | Reference cermet grade | KT20 (Koves) |
|---|---|---|
| Workpiece and operation | ||
| Workpiece material | 45 carbon steel (C45 / AISI 1045) | |
| Cut type | Continuous cut | |
| Operation | Bore + facing | |
| Test machine | CNC horizontal lathe | |
| Coolant | Coolant (flood) | |
| Tools compared — only the grade was changed | ||
| Tool manufacturer | Japanese cermet maker | Koves (KOVES) |
| Insert model | TNMG160408 | TNMG160408 |
| Chipbreaker | CQ | HQ |
| Insert grade | Reference cermet grade | KT20 |
| Cutting conditions — identical for both tools | ||
| Spindle speed S | 1800 min⁻¹ | |
| Table feed F | 240 mm/min | |
| Depth of cut ap | 0.5 mm | |
| Result | ||
| Tool life (parts/edge) | 1,000 | 1,200 |
| Outcome | Tool life 1.20× the reference grade (+20%) | |

Comparative cutting test on Carbon steel: KOVES KT20 TNMG160404 (R-VF) against the reference cermet grade the customer used before Tool life 1000 vs 900 parts per edge at identical cutting data (1.11× longer edge life). Operation: od + facing, continuous cut, cnc horizontal lathe.
| Item | Reference cermet grade | KT20 (Koves) |
|---|---|---|
| Workpiece and operation | ||
| Workpiece material | Carbon steel | |
| Part / feature | Fitting / joint | |
| Cut type | Continuous cut | |
| Operation | OD + facing | |
| Test machine | CNC horizontal lathe | |
| Coolant | Coolant (flood) | |
| Tools compared — only the grade was changed | ||
| Tool manufacturer | Korean cermet maker | Koves (KOVES) |
| Insert model | TNMG160404 | TNMG160404 |
| Chipbreaker | R-VF | R-VF |
| Insert grade | Reference cermet grade | KT20 |
| Cutting conditions — identical for both tools | ||
| Spindle speed S | 1980 min⁻¹ | |
| Depth of cut ap | 2.0 mm | |
| Result | ||
| Tool life (parts/edge) | 900 | 1,000 |
| Outcome | Tool life 1.11× the reference grade (+11%) | |

Comparative cutting test on 40Cr alloy steel (AISI 5140): KOVES KT20 VBMT11T304 (HQ) against the reference cermet grade the customer used before Tool life 300 parts per edge, matching the reference grade; the test was stopped before the wear limit. Operation: od + facing, continuous cut, cnc horizontal lathe.
| Item | Reference cermet grade | KT20 (Koves) |
|---|---|---|
| Workpiece and operation | ||
| Workpiece material | 40Cr alloy steel (AISI 5140) | |
| Cut type | Continuous cut | |
| Machined surface | Black skin (as-forged) | |
| Operation | OD + facing | |
| Test machine | CNC horizontal lathe | |
| Coolant | Coolant (flood) | |
| Tools compared — only the grade was changed | ||
| Tool manufacturer | Japanese cermet maker | Koves (KOVES) |
| Insert model | VBMT11T304 | VBMT11T304 |
| Chipbreaker | HQ | HQ |
| Insert grade | Reference cermet grade | KT20 |
| Cutting conditions — identical for both tools | ||
| Spindle speed S | 1800 min⁻¹ | |
| Table feed F | 110 mm/min | |
| Depth of cut ap | 0.2 mm | |
| Result | ||
| Tool life (parts/edge) | 300 | 300 |
| Outcome | Tool life equal — test stopped before the wear limit | |

Comparative cutting test on 20 carbon steel (C20 / AISI 1020): KOVES KT20 WNMG080404 (MT) against the reference cermet grade the customer used before Tool life 100 parts per edge, matching the reference grade; the test was stopped before the wear limit. Operation: od + facing, continuous cut, cnc horizontal lathe.
| Item | Reference cermet grade | KT20 (Koves) |
|---|---|---|
| Workpiece and operation | ||
| Workpiece material | 20 carbon steel (C20 / AISI 1020) | |
| Cut type | Continuous cut | |
| Operation | OD + facing | |
| Test machine | CNC horizontal lathe | |
| Coolant | Coolant (flood) | |
| Tools compared — only the grade was changed | ||
| Tool manufacturer | Japanese cermet maker | Koves (KOVES) |
| Insert model | WNMG080404 | WNMG080404 |
| Chipbreaker | HQ | MT |
| Insert grade | Reference cermet grade | KT20 |
| Cutting conditions — identical for both tools | ||
| Spindle speed S | 2400 min⁻¹ | |
| Table feed F | 400 mm/min | |
| Depth of cut ap | 1.5 mm | |
| Result | ||
| Tool life (parts/edge) | 100 | 100 |
| Outcome | Tool life equal — test stopped before the wear limit | |

Comparative cutting test on 20 carbon steel (C20 / AISI 1020): KOVES KT20 WNMG080404 (MT) against the reference cermet grade the customer used before Tool life 500 parts per edge, matching the reference grade; the test was stopped before the wear limit. Operation: od + facing, continuous cut, cnc horizontal lathe.
| Item | Reference cermet grade | KT20 (Koves) |
|---|---|---|
| Workpiece and operation | ||
| Workpiece material | 20 carbon steel (C20 / AISI 1020) | |
| Cut type | Continuous cut | |
| Machined surface | Black skin (as-forged) | |
| Operation | OD + facing | |
| Test machine | CNC horizontal lathe | |
| Coolant | Coolant (flood) | |
| Tools compared — only the grade was changed | ||
| Tool manufacturer | Japanese cermet maker | Koves (KOVES) |
| Insert model | WNMG080404 | WNMG080404 |
| Chipbreaker | TS | MT |
| Insert grade | Reference cermet grade | KT20 |
| Cutting conditions — identical for both tools | ||
| Spindle speed S | 1800 min⁻¹ | |
| Table feed F | 280 mm/min | |
| Depth of cut ap | 1.0 mm | |
| Result | ||
| Tool life (parts/edge) | 500 | 500 |
| Outcome | Tool life equal — test stopped before the wear limit | |

Comparative cutting test on 20 carbon steel (C20 / AISI 1020): KOVES KT20 WNMG080404 (MT) against the reference cermet grade the customer used before Tool life 600 vs 550 parts per edge at identical cutting data (1.09× longer edge life). Operation: od + facing, continuous cut, cnc horizontal lathe.
| Item | Reference cermet grade | KT20 (Koves) |
|---|---|---|
| Workpiece and operation | ||
| Workpiece material | 20 carbon steel (C20 / AISI 1020) | |
| Cut type | Continuous cut | |
| Operation | OD + facing | |
| Test machine | CNC horizontal lathe | |
| Coolant | Coolant (flood) | |
| Tools compared — only the grade was changed | ||
| Tool manufacturer | Japanese cermet maker | Koves (KOVES) |
| Insert model | WNMG080404 | WNMG080404 |
| Chipbreaker | TS | MT |
| Insert grade | Reference cermet grade | KT20 |
| Cutting conditions — identical for both tools | ||
| Spindle speed S | 2200 min⁻¹ | |
| Table feed F | 240 mm/min | |
| Depth of cut ap | 1.0 mm | |
| Result | ||
| Tool life (parts/edge) | 550 | 600 |
| Outcome | Tool life 1.09× the reference grade (+9%) | |

Comparative cutting test on 20 carbon steel (C20 / AISI 1020): KOVES KT20 CCMT060204 (FG) against the reference cermet grade the customer used before Tool life 300 parts per edge, matching the reference grade; the test was stopped before the wear limit. Operation: bore, continuous cut, cnc horizontal lathe.
| Item | Reference cermet grade | KT20 (Koves) |
|---|---|---|
| Workpiece and operation | ||
| Workpiece material | 20 carbon steel (C20 / AISI 1020) | |
| Cut type | Continuous cut | |
| Machined surface | Pre-machined surface | |
| Operation | Bore | |
| Test machine | CNC horizontal lathe | |
| Coolant | Coolant (flood) | |
| Tools compared — only the grade was changed | ||
| Tool manufacturer | Japanese cermet maker | Koves (KOVES) |
| Insert model | CCMT060204 | CCMT060204 |
| Chipbreaker | HQ | FG |
| Insert grade | Reference cermet grade | KT20 |
| Cutting conditions — identical for both tools | ||
| Spindle speed S | 1800 min⁻¹ | |
| Table feed F | 200 mm/min | |
| Depth of cut ap | 0.25 mm | |
| Result | ||
| Tool life (parts/edge) | 300 | 300 |
| Outcome | Tool life equal — test stopped before the wear limit | |

Comparative cutting test on 20Cr alloy steel (AISI 5120): KOVES KT20 TNMG160404 (MT) against the reference cermet grade the customer used before Tool life 400 vs 300 parts per edge at identical cutting data (1.33× longer edge life). Operation: od + facing, continuous cut, cnc horizontal lathe.
| Item | Reference cermet grade | KT20 (Koves) |
|---|---|---|
| Workpiece and operation | ||
| Workpiece material | 20Cr alloy steel (AISI 5120) | |
| Cut type | Continuous cut | |
| Machined surface | Black skin (as-forged) | |
| Operation | OD + facing | |
| Test machine | CNC horizontal lathe | |
| Coolant | Coolant (flood) | |
| Tools compared — only the grade was changed | ||
| Tool manufacturer | Japanese cermet maker | Koves (KOVES) |
| Insert model | TNMG160404 | TNMG160404 |
| Chipbreaker | TS | MT |
| Insert grade | Reference cermet grade | KT20 |
| Cutting conditions — identical for both tools | ||
| Spindle speed S | 2100 min⁻¹ | |
| Table feed F | 350 mm/min | |
| Depth of cut ap | 1.5 mm | |
| Result | ||
| Tool life (parts/edge) | 300 | 400 |
| Outcome | Tool life 1.33× the reference grade (+33%) | |

Comparative cutting test on 45 carbon steel (C45 / AISI 1045): KOVES KT20 TNMG160404 (MT) against the reference cermet grade the customer used before Tool life 300 parts per edge, matching the reference grade; the test was stopped before the wear limit. Operation: facing, interrupted cut, cnc horizontal lathe.
| Item | Reference cermet grade | KT20 (Koves) |
|---|---|---|
| Workpiece and operation | ||
| Workpiece material | 45 carbon steel (C45 / AISI 1045) | |
| Cut type | Interrupted cut | |
| Machined surface | Black skin (as-forged) | |
| Operation | Facing | |
| Test machine | CNC horizontal lathe | |
| Coolant | Coolant (flood) | |
| Tools compared — only the grade was changed | ||
| Tool manufacturer | Japanese cermet maker | Koves (KOVES) |
| Insert model | TNMG160404 | TNMG160404 |
| Chipbreaker | HQ | MT |
| Insert grade | Reference cermet grade | KT20 |
| Cutting conditions — identical for both tools | ||
| Spindle speed S | 1680 min⁻¹ | |
| Feed per edge fz | 0.13 mm/rev | |
| Table feed F | 200 mm/min | |
| Depth of cut ap | 0.2 mm | |
| Result | ||
| Tool life (parts/edge) | 300 | 300 |
| Outcome | Tool life equal — test stopped before the wear limit | |

Comparative cutting test on 20 carbon steel (C20 / AISI 1020): KOVES KT20 WNMG080404 (MT) against the reference cermet grade the customer used before Tool life 140 vs 90 parts per edge at identical cutting data (1.56× longer edge life). Operation: facing, interrupted cut, cnc horizontal lathe.
| Item | Reference cermet grade | KT20 (Koves) |
|---|---|---|
| Workpiece and operation | ||
| Workpiece material | 20 carbon steel (C20 / AISI 1020) | |
| Cut type | Interrupted cut | |
| Operation | Facing | |
| Test machine | CNC horizontal lathe | |
| Coolant | Coolant (flood) | |
| Tools compared — only the grade was changed | ||
| Tool manufacturer | Japanese cermet maker | Koves (KOVES) |
| Insert model | WNMG080404 | WNMG080404 |
| Chipbreaker | TS | MT |
| Insert grade | Reference cermet grade | KT20 |
| Cutting conditions — identical for both tools | ||
| Cutting speed Vc | 72 m/min | |
| Table feed F | 200 mm/min | |
| Depth of cut ap | 0.5 mm | |
| Result | ||
| Tool life (parts/edge) | 90 | 140 |
| Outcome | Tool life 1.56× the reference grade (+56%) | |

Tool life is counted in parts per edge as recorded by the customer's own production counting. Every test ran on the customer's machine with the customer's clamping, coolant and cycle — so the numbers move with rigidity, blank condition and batch. Reference grades are anonymised; the insert model and chipbreaker are shown in full so you can identify the tool that was compared.
Comparative data from Koves cutting tests and customer field applications. Results depend on workpiece, machine and setup; validate on your own production before adopting parameters.
Send us the workpiece drawing, material and the cutting data you run today. We run the same side-by-side format against your current grade and share the numbers.
Contact usTell us the material, hardness and machine — our engineers reply with a grade recommendation and starting cutting data, at no obligation.
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