ISO 513 application group · brand-neutral
ISO M grades — stainless steel
Two different M scales, and they are not the same. On a workpiece chart, M plus a number describes the material you are cutting. On an insert box, M plus a number describes what the grade is built for. The letter is shared, so a M-group material is cut with M-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 M is the stainless steel group. 149 grades from 15 manufacturers are placed somewhere in it across 6 application classes, according to the comparison charts the makers publish themselves.
What the number after the M 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 M 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.
M10
34 grades from 12 manufacturers are placed at M10. The 11 below have a cross-brand equivalence page: ISCAR IC808 · Kennametal KCPM20 · NTK DM4 · NTK ZM3 · Sandvik GC1025 · Sandvik GC1030 · Sandvik GC1105 · Sumitomo AC6020M · Sumitomo ACM200 · Sumitomo EH510 · Walter WSM01 and 23 more.
M15
14 grades from 9 manufacturers are placed at M15. The 10 below have a cross-brand equivalence page: ISCAR IC807 · Kennametal KCM25B · Kennametal KCS10 · Kennametal KCS10B · Kyocera PR930 · MOLDINO IP100S · Sandvik GC2220 · TaeguTec TT5080 · Tungaloy GH110 · Walter WSM20S and 4 more.
M20
63 grades from 15 manufacturers are placed at M20. The 14 below have a cross-brand equivalence page: Dijet JC5015 · Dijet JC8015 · ISCAR IC808 · Kennametal KC525M · Kennametal KCM25B · Kennametal KCPM20 · Kennametal KCPM30 · Kyocera PR1525 · MOLDINO HG8025 · MOLDINO IP100S · NTK DM4 · NTK DT4 · NTK ZM3 · Sandvik GC2220 and 49 more.
M30
70 grades from 14 manufacturers are placed at M30. The 14 below have a cross-brand equivalence page: Dijet JC5015 · ISCAR IC928 · Kennametal KC5025 · Kennametal KC725M · Kennametal KC735M · Kennametal KCPM30 · Kennametal KCPM40 · Kennametal KCU25 · Kyocera PR1525 · Kyocera PR1725 · MOLDINO GM25 · MOLDINO GM8035 · MOLDINO GX30 · MOLDINO JM4160 and 56 more.
M35
17 grades from 8 manufacturers are placed at M35. The 6 below have a cross-brand equivalence page: Dijet JC5015 · Kennametal KC5025 · Kennametal KCU25 · Kyocera PR1725 · Sumitomo AC530U · Tungaloy AH6225 and 11 more.
M40
19 grades from 11 manufacturers are placed at M40. The 13 below have a cross-brand equivalence page: ISCAR IC328 · ISCAR IC330 · Kennametal KC725M · MOLDINO JM4160 · Mitsubishi MP7035 · Mitsubishi US735 · Mitsubishi VP30RT · Sandvik GC2035 · Seco TM4000 · Sumitomo ACM300 · Tungaloy AH140 · Tungaloy AH6235 · Walter WSP45 and 6 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 M 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.