ISO P — Steel · P02
P02 — Medium carbon steel
Hardness range: 160–220 HB. Part of the ISO P — Steels group. Steel is the most widely machined material. Carbon and alloy steels are the target material for the majority of turning and milling operations. Hardness ranges from ~125 HB (low-carbon) to 350 HB (high-strength structural). CVD-coated carbide (TiCN/Al₂O₃ multilayer) dominates. Positive geometry for finishing, negative for heavy roughing.
Material profile — P02
- ISO designation
- P02 (ISO P — Steels)
- Material
- Medium carbon steel
- Hardness
- 160–220 HB
- ISO group colour
- Steel
Tooling guidance — P-group
- Group summary
- CVD-coated carbide at Vc 200–400 m/min. Positive geometry for finishing, negative for roughing.
Insert selection for medium-carbon steel (1045) — starting point
- ISO application class
- P (steel). Medium-carbon steel (1045) is the bread-and-butter turning material: less gummy than mild steel and predictable. Match the ISO P class across brands rather than the brand name (Sandvik, Kennametal, Iscar, Walter, Seco and Mitsubishi each publish one), then confirm the exact grade for your condition.
- Grade & coating
- CVD-coated carbide, P15–P25; tougher for roughing, harder for finishing.
- Geometry
- Negative for roughing and economy; positive for finishing and low-rigidity work. Medium chipbreaker.
- Starting parameters
- Vc ≈ 180–280 m/min, fn ≈ 0.10–0.40 mm/rev. Confirm in the advisor or on a sample part.
Selection table: medium-carbon steel (1045)
| Operation | Geometry | ISO class | Coating family | Coolant | First check |
|---|---|---|---|---|---|
| Roughing | Negative for roughing and economy, medium chipbreaker | P15–P25 (tougher end) | CVD-coated carbide | Per process | Chip control: match the chipbreaker to depth and feed |
| Finishing | Positive for finishing, medium chipbreaker | P15–P25 (harder end) | CVD-coated carbide | Per process | Flank wear sets tool life: balance Vc and grade |
| Interrupted cut | Negative with a robust chipbreaker | P15–P25 (tougher end) | CVD-coated carbide | Per process | Crater wear at high speed: ease Vc |
| Low rigidity / thin wall | Positive for low-rigidity work | P15–P25 | CVD-coated carbide | Per process | Built-up edge at low speed: raise Vc, sharper edge |
medium-carbon steel (1045): what goes wrong, and what to check first
- Crater wear at high speed
- Heat behind the edge; use a CVD grade and ease Vc.
- Flank wear
- Normal abrasion that sets tool life; balance Vc and grade.
- Built-up edge at low speed
- Raise Vc, sharper edge, add coolant.
- Chip control
- Match the chipbreaker to depth and feed.
Reference data
Frequently asked questions
What insert for medium-carbon steel like 1045?
A CVD-coated carbide, P15–P25. Match the ISO P class across brands and confirm in the advisor.
What cutting speed for 1045 with carbide?
Roughly Vc 180–280 m/min, fn 0.10–0.40 mm/rev. Confirm on a sample part.
Negative or positive insert for 1045?
Negative for roughing and economy, positive for finishing or low-rigidity setups.
Why crater wear on medium-carbon steel?
Heat at higher speeds wears a crater; use a CVD grade and ease the speed.
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Grade designations in this group
Each page cross-references the EN, Werkstoffnummer, AISI/UNS and JIS designations for one material, with the ISO machining group it falls in.
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