Test report
| 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%) | |
Result and comparison basis
At identical cutting data the KT20 edge produced 400 parts per edge against 300 for the reference grade — 33% longer edge life with the same insert geometry and the same cycle. Only the grade changed; nothing in the process had to be adjusted.
Chipbreaker change: the reference tool ran TS, the Koves tool ran MT — both cut the same feature at the same parameters, so the difference is attributable to the grade and its edge preparation.
Comparison basis: the cermet grade the customer was running before the test, anonymised as “Reference cermet grade”. Insert model, chipbreaker and all cutting data are shown in full.
Related series
- TNMG Negative Cermet Turning Inserts — M Grade — 14 models
Comparative data from a Koves customer cutting test. Competitor grades are anonymised as reference grades. Results depend on workpiece, machine and setup; validate on your own production before adopting parameters.
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