100MnCrW4 is the same material your supplier may list as AISI O1 or JIS SKS3. This page maps the designations across standards and gives the ISO P-group machining starting point, brand-neutral.
| System | Designation |
|---|---|
| EN (EU) | 100MnCrW4 |
| Werkstoffnummer | 1.2510 |
| AISI / ASTM / UNS (US) | AISI O1 (UNS T31501) |
| JIS (Japan) | SKS3 (nearest) |
Compiled from the public standard designation systems (EN 10027, SAE/AISI, ASTM, UNS, JIS). Entries marked “nearest” are the closest commonly-cited counterpart, not a drop-in equivalent. Always verify against the material certificate.
The friendliest common tool steel to machine annealed; gauge-plate stock cuts predictably at low-alloy-steel data. Hardened, it moves to H-group treatment.
| ISO group | Starting Vc (coated carbide, turning) | Feed fn |
|---|---|---|
| P P · Steel | 150–350 m/min · 490–1150 sfm | 0.1–0.5 mm/rev · .004–.020 ipr |
Group-level starting range from our speeds & feeds guide; convert to RPM with the speeds & feeds calculator. Condition, subgroup and operation shift the number — the material page has the detail: ISO P · Cold-work tool steel.
Related materials: H13 / 1.2344 · D2 / 1.2379 · D3 / 1.2080 · O2 / 1.2842 · P20 / 1.2311 · M2 / 1.3343
100MnCrW4 (Werkstoffnummer 1.2510) corresponds to AISI O1 (UNS T31501). In JIS terms the counterpart is SKS3 (nearest).
It is an ISO P-group material, so the starting window is 150–350 m/min · 490–1150 sfm at 0.1–0.5 mm/rev · .004–.020 ipr for coated-carbide turning, adjusted for condition and operation. For a grounded, brand-neutral pick — grade, geometry and cutting data across 13 brands — ask the advisor.
They designate the same composition under different systems, but the drawing standard governs: certificates, tolerances and delivery-condition requirements differ between standards even for equivalent chemistry. Substitute only with the certificate in hand.
Knowing the material is half the job; picking the grade and cutting data for the operation is the other half. That is what the advisor does, grounded in catalog data and honest when there is no verified match.