ISO 513 application group · brand-neutral
ISO K grades — cast iron
Two different K scales, and they are not the same. On a workpiece chart, K plus a number describes the material you are cutting. On an insert box, K plus a number describes what the grade is built for. The letter is shared, so a K-group material is cut with K-group grades. The numbers are not: a workpiece subgroup number and a grade's application number come from different scales and must never be matched to each other. Everything on this page is the grade side.
ISO K is the cast iron group. 177 grades from 14 manufacturers are placed somewhere in it across 6 application classes, according to the comparison charts the makers publish themselves.
What the number after the K means
Inside a letter the two-digit number is a position on one axis: the low numbers are the wear-resistant, harder grades meant for finishing cuts at higher speed and lighter load, the high numbers are the tougher grades meant for roughing, interrupted cuts and less stable setups. It is a continuum, not a set of boxes, and makers place their own grades on it.
Grades at each K class
Two grades in the same class are built for the same job. They are not identical: substrate, cobalt content, coating and edge preparation still differ, and so will tool life and the cutting data you should start from.
K01
15 grades from 7 manufacturers are placed at K01. The 3 below have a cross-brand equivalence page: Mitsubishi MB5015 · Mitsubishi MB710 · Sumitomo BN500 and 12 more.
K05
26 grades from 12 manufacturers are placed at K05. The 4 below have a cross-brand equivalence page: Kyocera CA4505 · Kyocera PV7005 · Sumitomo AC4010K · Tungaloy T5105 and 22 more.
K10
91 grades from 14 manufacturers are placed at K10. The 14 below have a cross-brand equivalence page: ISCAR IC5010 · ISCAR IC807 · ISCAR IC9150 · Kennametal KCK15B · Kennametal KCS10 · Kennametal KCS10B · Kyocera CA4505 · Kyocera CA4515 · Kyocera PV7005 · MOLDINO CH550 · Mitsubishi HTi10 · Mitsubishi MB5015 · Mitsubishi MB710 · Mitsubishi MC5015 and 77 more.
K15
22 grades from 10 manufacturers are placed at K15. The 14 below have a cross-brand equivalence page: ISCAR IC5010 · Kennametal KCK15B · Kyocera CA4515 · Kyocera TN60 · MOLDINO CZ25 · Mitsubishi MC5015 · Mitsubishi MC5115 · Mitsubishi UC5115 · Sumitomo AC4015K · TaeguTec TT7015 · Tungaloy AT9530 · Tungaloy T5115 · Tungaloy T515 · Walter WAK20 and 8 more.
K20
77 grades from 13 manufacturers are placed at K20. The 14 below have a cross-brand equivalence page: ISCAR IC9150 · Kennametal KC5025 · Kennametal KCU25 · MOLDINO CY9020 · MOLDINO GM8020 · Mitsubishi MBS140 · Mitsubishi MC5015 · Mitsubishi UC5115 · Seco MK2050 · Sumitomo AC4015K · Sumitomo AC530U · Sumitomo BNS8125 · TaeguTec TT7015 · Tungaloy BX90S and 63 more.
K30
19 grades from 7 manufacturers are placed at K30. The 7 below have a cross-brand equivalence page: Kennametal KC522M · MOLDINO CY250 · Mitsubishi MBS140 · Seco MK2050 · Sumitomo BNS8125 · Tungaloy BX90S · Tungaloy BXC90 and 12 more.
Where these numbers come from
Every placement above is read from a grade comparison chart published by a manufacturer, cross-checked against other makers' charts. Nothing is inferred from price, availability or popularity, and no manufacturer pays to appear here. Something wrong on this page? research@cuttingtoolsai.eu.
Looking for the workpiece side instead — which steel, stainless or iron falls in which group? That is the ISO material groups chart.
Are you overpaying on your ISO K inserts? Paste your insert list and get a cost audit in about 30 seconds: cross-brand equivalents at the same ISO application position, and where you are likely overpaying. No signup, no sales call.
Ask about your own case
Material, operation, machine — get a grade and a starting cutting data set, grounded in the same reference data.