Workpiece material / Tool steel

O2 Tool Steel speeds and feeds

Starting surface speeds and chip loads for milling O2 Tool Steel. Every value below is cross-checked against published sources and linked, so you can re-verify it yourself. Starting points, not limits.

Identification

W.Nr: 1.2842
DIN / EN: 90MnCrV8
AISI / SAE: O2
UNS: T31502
Brands: Bohler K720, 9Mn2V
Hardness: 200-229 HB
Condition: Soft-annealed (max 229 HB per EN ISO 4957) - the state O2 is machined in before hardening.
ISO 513 group: P

Cutting data / sourcedClick any source to check

Value	Used	Provider readings (each linked)
Surface speed, HSS (estimated)	40 SFM	40 Machining Doctor - O1 tool steel data sheet (nearest tabulated O-series grade) - HSS end milling, O-series annealed class; single source, treat as a starting point
Surface speed, carbide (estimated)	200 SFM	310 Machining Doctor - O1 tool steel data sheet (nearest tabulated O-series grade) - O2 not separately tabulated; O1 (nearest O-series cold-work grade) indexable milling 310-430 SFM. Solid end mills run slower, so the shipped 200 SFM is a conservative solid-tool starting point.
Chip load @ 0.25" (estimated)	0.0008 in/tooth	0.0008 Machining Doctor - O1 tool steel data sheet (nearest tabulated O-series grade) - class-typical cold-work tool steel at a 1/4 in end mill; not grade-specific

Chip load by end-mill diameter in/tooth

0.125"	0.25"	0.5"
0.0004	0.0008	0.0016

Cutting-power model class-typical

Constant	Value	Readings
Kc1.1 (specific cutting force) (estimated)	1,900 N/mm2	1,900 Sandvik Coromant - specific cutting force (Kc) by ISO material group - ISO P tool-steel group-typical Kc1.1; not tuned to this grade
mc (chip-thickness exponent) (estimated)	0.25	ISO P group-typical - see notes
Unit power (estimated)	1.50 HP/(in3/min)	ISO P group-typical - see notes

The power-model constants (Kc1.1, mc, unit power) are class-typical values for the ISO P group, used only for a rough spindle-power estimate. Only their relative ordering and internal consistency are verified, never tuned to match any vendor.

Notes

O2 (1.2842 / 90MnCrV8) is an oil-hardening manganese cold-work tool steel, machined soft-annealed (about 200-229 HB, max 229 HB per EN ISO 4957) before hardening. Grade identification (designations, condition, hardness) is from SteelPRO. Grade-specific published milling speeds are scarce, so the cutting parameters are anchored to O1 - the nearest tabulated O-series cold-work grade (indexable milling 310-430 SFM) - and shipped as conservative solid-tool starting points, all flagged estimated. The power-model constants are ISO P tool-steel class-typical values for a rough power estimate only. Verify against your tool maker or shop data.

Verify this yourself

Every number above links to the provider that publishes it. Open two or more and confirm they agree with what is shown here. Full source list:

Take these into the feeds and speeds calculator for RPM, feed and power. Start a little under these numbers on a light or flexible setup.