ISO 513 application group · brand-neutral
ISO H grades — hardened materials
Two different H scales, and they are not the same. On a workpiece chart, H plus a number describes the material you are cutting. On an insert box, H plus a number describes what the grade is built for. The letter is shared, so a H-group material is cut with H-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 H is the hardened materials group. 64 grades from 9 manufacturers are placed somewhere in it across 4 application classes, according to the comparison charts the makers publish themselves.
What the number after the H 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 H 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.
H01
19 grades from 8 manufacturers are placed at H01. The 6 below have a cross-brand equivalence page: Kyocera KBN05M · Mitsubishi MB8110 · Seco CBN060K · Sumitomo BN2000 · Sumitomo BNC2115 · Tungaloy BXM10 and 13 more.
H10
24 grades from 9 manufacturers are placed at H10. The 14 below have a cross-brand equivalence page: ISCAR IB25HA · Kyocera KBN05M · Kyocera KBN25M · Mitsubishi MB8025 · Mitsubishi MB8110 · NTK B36 · NTK B6K · Seco CBN060K · Seco CBN150 · Seco CBN160C · Sumitomo BN2000 · Sumitomo BNC2020 · Sumitomo BNC2115 · Tungaloy BXM10 and 10 more.
H20
23 grades from 9 manufacturers are placed at H20. The 8 below have a cross-brand equivalence page: ISCAR IB25HA · Kyocera KBN25M · Mitsubishi MB8025 · NTK B36 · NTK B6K · Seco CBN150 · Seco CBN160C · Sumitomo BNC2020 and 15 more.
H30
12 grades from 7 manufacturers are placed at H30: ISCAR IB90 · Kyocera KBN35M · Kyocera KBN900 · Mitsubishi BC8130 · Mitsubishi MB8130 · NTK B40 · Seco CH3515 · Sumitomo BN350 · Sumitomo BNC300 · Tungaloy BR35F · Tungaloy BX380 · Tungaloy BXC50.
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 H 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.