Technical guide · 2026-08-14
Cold-Work Tool Steel
Cold-work tool steels serve dies and tools operating near ambient temperature, where abrasive or adhesive wear must be traded against chipping resistance and heat-treatment movement rather than hot-strength retention.
01
Definition and boundary
Use this group for room-temperature forming and cutting loads; it does not cover sustained red-heat cutting, die-casting heat cycling or mold-surface requirements as the primary selection driver.
Reference information only: final acceptance is controlled by the ordered product specification, condition, dimensions and certified test results.
02
How the material system works
Chromium and carbide formers raise hardenability and wear resistance.
Carbide volume and distribution influence edge stability and grindability.
Quench route, retained austenite and tempering control dimensional change.
03
Representative grades and systems
| Grade or system | Selection focus | Qualification |
|---|---|---|
| D2 | High wear resistance for stable, adequately supported tooling. | Confirm the governing product specification, delivery condition, section size and acceptance tests before treating designations as interchangeable. |
| A2 | Air-hardening balance of toughness, wear and dimensional control. | Confirm the governing product specification, delivery condition, section size and acceptance tests before treating designations as interchangeable. |
| O1 | Oil-hardening grade for smaller tools and accessible heat treatment. | Confirm the governing product specification, delivery condition, section size and acceptance tests before treating designations as interchangeable. |
04
Properties and trade-offs
Abrasive-wear resistance
Compressive strength at working hardness
Chipping resistance and dimensional stability
05
Product forms and supply conditions
06
Applications and selection
Applications and selection
- Blanking and trimming dies
- Cold-forming punches and rolls
- Gauges, knives and shear tooling
Properties and trade-offs
- Choose D-series only when wear gain justifies reduced toughness.
- Use A-series where distortion control and balanced performance dominate.
- Check O-series section size and quench severity before specifying.
07
Fabrication, durability and inspection
Protect surfaces from decarburization during austenitizing.
Use staged preheating and controlled quenching for complex sections.
Finish-grind with thermal control to avoid burns and tensile cracking.
08
Procurement checklist
- Order annealed hardness and carbide-quality limits.
- State machining allowance, surface decarburization and ultrasonic needs.
- Define final hardness, temper sequence and dimensional-stability verification.
09
Standards, sources and review
Standards and designation context
- ASTM A681 alloy tool-steel scope
- ASTM A600 where high-speed grades apply
- Buyer drawing and heat-treatment specification