TS · tool steel
Tool Steel D3 (high carbon, high chromium)
More carbon and more carbide than D2, so more wear resistance and less toughness - and slightly harder to machine and grind in the annealed state.
Quoting this material
- Typical lead time
- 14–22 working days
- Condition
- Annealed; hardened and tempered for service
- Achievable finish
- Ra 0.8 µm after grinding typical · Ra 0.2 µm (polished) best
Machined in-house to your drawing: see the precision CNC machining service and the machine and inspection capability it runs on.
Machinability
Our own 1–10 shop ranking, not a published index: 10 is free-cutting brass C360, 1 is Inconel 718. It ranks how a material behaves on the floor - cycle time, chip control and tool life together. Where a published index exists it is quoted in the note.
More carbon and more carbide than D2, so more wear resistance and less toughness - and slightly harder to machine and grind in the annealed state.
Properties as supplied
| Parameter | Value | Unit |
|---|---|---|
| Hardness (working) | 58–62 | HRC |
| Wear resistance | Very high | - |
| Toughness | Lower than D2 | - |
| Grindability | Difficult | - |
| Thermal conductivity | 20 | W/m·K |
| Modulus of elasticity | 210 | GPa |
Hardness, tensile and thermal figures are typical published values for the condition stated. Actual mill certificates govern; send the specification with the drawing and we confirm against the certificate before the material is cut.
Condition
Annealed; hardened and tempered for service
Heat treatment
Austenitise around 980–1,020 °C, quench and temper. Similar movement to D2 with slightly more risk at sharp section changes because of the higher carbon.
Achievable surface finish
Ra 0.8 µm after grinding
Ra 0.2 µm (polished)
Polishes to an excellent finish; grindability is worse than D2 because of the carbide volume.
Tooling and cutting parameters
Cutting speed
- 70–140 m/min annealed (carbide) · 30–45 m/min at 60 HRC (CBN)
Feed
- 0.08–0.20 mm/rev turning · 0.05–0.12 mm/tooth milling
Tooling
- Coated carbide annealed; CBN or EDM for hardened
Coolant
- Flood
Starting points for carbide on a rigid setup, not a guarantee. The right numbers depend on the machine, the toolholder and the fixturing - ask and we will say what we would actually run.
Typical applications
- Long-run blanking dies
- Abrasive-material forming tools
- Wear plates in high-wear service
- Slitter and shear tooling
- Powder compaction tooling
DFM notes for this grade
- Specify it only when D2 has actually worn out - the extra wear resistance costs toughness and grinding time
- Grinding cost can exceed the material cost difference; budget for it explicitly
- Not for a shock-loaded tool: D3 is the most brittle of the common cold-work grades
Questions buyers ask
- When is D3 justified over D2?
- High-volume runs of abrasive material where D2 wears the edge away in a matter of days. For most work D2 is the better balance; D3 is for the case where the die life is the constraint on the whole production line.
- Is D3 hard to grind?
- Yes, and that is a real cost. The high carbide volume loads a conventional wheel and burns the surface if the wheel is not dressed often enough, which introduces tensile stress in the surface - the opposite of what a tool steel needs.