Measured results from Koves internal cutting tests and customer field applications on hardened and case-hardening steels: tool life, wear behaviour and the exact cutting conditions behind every number. Reference grades in comparisons are anonymized.
In continuous turning of hardened bearing steel (HRC 62) at 180 m/min, KBN5010 showed the lowest flank wear of all grades in the comparison and delivered the longest tool life of the test.
At 250 m/min high-speed continuous turning of HRC 60 steel, the coated KBCN5010 grade showed the least flank wear of the three compared grades.
In medium-interrupted turning of HRC 60 steel, KBN6020 balanced wear resistance against edge chipping resistance and beat both the higher-hardness grade and a competitor reference grade in overall performance.
KBN6020 carried a heavy feed of 0.2 mm/rev through interrupted turning of HRC 60 steel with less wear than the compared grades — cutting remained stable throughout the test.
In strongly interrupted turning of HRC 50 alloy steel, the coated KBCN7030 grade delivered the best combination of impact endurance and flank wear among the compared grades.
Interrupted turning at 180 m/min and 0.2 mm/rev completed with no abnormal edge damage and lower wear than the competitor reference grade.
Two field tests reached 890 and 850 parts respectively, against 650 and 720 parts for the Japanese reference grade — roughly 30% longer tool life at 215 m/min.
Coated KBCN5010 reached 1,780 and 1,820 parts over two tests; the uncoated grade reached 1,600/1,650 — on par with the leading competitor reference grade (1,800/1,805 parts).
KBN6020 delivered 1,102 and 1,050 parts in two tests; the competitor grooving insert reached only 450 and 500 — more than double the tool life at 160 m/min.
On interrupted gear face turning at 58 HRC, KBN7030 machined 70 parts against 45 for the reference grade — about 55% longer life.
Gear bore interrupted turning at 58–60 HRC: 170 parts versus 110 for the competitor grade, a roughly 55% life improvement.
Two edges machined 2,229 parts with flank wear of only 0.03/0.04 mm; the reference grade failed at 2,056 parts with 0.3 mm wear and edge chipping. Cutting speed 370 m/min (1,214 sfm), dry.
Coated KBCN9020 reached 75–80 parts versus 35–45 for the uncoated grade. For strongly interrupted machining of steel above 60 HRC, the coated grade is recommended.
In a same-condition comparison on heavy interrupted turning (interrupted ratio above 30%) of 60 HRC shafts, KBN9530 ranked first and KBN7030 second.
Machined 1.5 times the number of parts of the previously used grade with better surface finish (Rz max 4.8 μm) at 0.35 mm/rev feed.
Stable surface finish with at least 1.1 times the part count of the previously used grade.
Life extended 1.5 times with stable surface finish, Ra below 0.8 μm.
Halved the production time lost to tool changes, raising overall line productivity at 250 m/min.
Tool life extended 2.5 times, securing a stable machining count per edge.
A full day of machining at 110 m/min without changing the cutting edge.
1.2 times the part count of the previous grade at the Rz < 6.3 μm life criterion.
Suppressed edge breakage in heavy interrupted cutting; life extended to 1.4 times the previous grade.
No breakage in heavy interrupted turning of large-diameter shafts (φ228 mm), enabling stable machining.
Life extended 1.3 times; the cutting condition was rolled out to parallel operations.
Three times the part count of the previous grade while surface roughness stayed within specification — the edge could still be used.
Superior wear resistance delivered at least 1.2 times the part count of the previous grade.
600 parts grooved per edge against 270 with the previously used grade.
Under identical cutting conditions, life extended by more than 1.5 times.
Improved machined-surface roughness with stable results at 0.22 mm/rev feed.
Eliminated edge breakage; tool life roughly doubled.
Stable part quality with life extended beyond 1.5 times the previous grade.
No abnormal damage; life extended to 1.5 times the previous grade.
1.5 times the part count of the previously used grade.
No edge chipping and twice the part count of the previous grade.
No abnormal damage with at least 1.5 times the part count of the previously used grade.
Fine boring of stacked oscillator plates in hardened 40CrMo (HRC 55-58) at 119 m/min, 0.08 mm/rev. The cut is essentially continuous with light interruption over the stacked joint and uneven stock of 0.3-0.5 mm, and bore tolerance is held at +0.03 mm with Ra below 0.8. After three-corner testing the insert reached about 10 assemblies per corner - matching the previously used reference grade - with stable sizing and one adjustment per corner. The customer approved a 40-piece batch trial for series production.
Comparative data from Koves internal cutting tests and customer field applications. Competitor grades are anonymized as reference grades. Results depend on workpiece, machine and setup; validate on your own production before adopting parameters.
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