Tool steel is not a single material. It is a broad group of steels engineered for cutting, forming, stamping, forging, moulding and other applications where hardness, wear resistance, toughness or resistance to elevated temperatures is required.
Choosing the correct grade therefore starts with understanding the major tool steel families.
This guide provides a practical tool steel grades chart for engineers, mould makers, purchasing teams and manufacturers comparing common AISI, DIN and industrial tool steel grades.
Technical note: Grade names from different standards may be similar in application without being chemically identical. Always confirm the governing material standard before substitution.
Tool Steel Grades at a Glance
| Type | Common Grades | Main Properties | Typical Applications |
|---|---|---|---|
| Cold Work | D2, D3, A2, O1, DC53 | Wear resistance, hardness, dimensional stability | Stamping, blanking, forming |
| Shock Resistant | S1, S7 | High impact toughness | Punches, chisels, heavy-duty tools |
| Hot Work | H11, H13, H10, 1.2714 | Hot strength, thermal fatigue resistance | Die casting, forging, extrusion |
| High Speed Steel | M2, M42, T1 | High hardness and red hardness | Drills, taps, cutters |
| Plastic Mould Steel | P20, 1.2312, 1.2738, 1.2316, NAK80 | Machinability, polishability, stability | Injection moulds |
| Wear-Resistant Tool Steel | D2, D3, 1.2601 | High carbide content and wear resistance | Long-run dies and cutting tools |
Cold Work Tool Steel Grades
Cold work tool steels are designed primarily for tooling operating near room temperature.
D2 / 1.2379
D2 combines high wear resistance with useful toughness and dimensional stability.
Typical applications include:
- Blanking dies
- Stamping dies
- Shear blades
- Forming dies
- Thread rolling tools
- Wear-resistant components
D3 / 1.2080
D3 places greater emphasis on abrasive wear resistance.
It is commonly selected for long-running cold work tools where severe impact loading is limited.
A2 / 1.2363
A2 is often selected when additional toughness and reduced risk of chipping are more important than achieving the maximum wear resistance available from D-series steels.
Shock-Resistant Tool Steels
S-series tool steels are engineered around impact resistance.
S7
S7 combines relatively high hardness with excellent toughness.
Common applications include punches, chisels, forming tools and components exposed to repeated impact.
Hot Work Tool Steel Grades
Hot work steels must retain useful properties while repeatedly exposed to elevated temperatures.
H13 / 1.2344
H13 is one of the most widely used hot work tool steels because it provides a balanced combination of:
- Hot strength
- Toughness
- Thermal fatigue resistance
- Wear resistance
- Hardenability
It is widely used for die casting, hot extrusion and hot forging.
H11 / 1.2343
H11 is closely associated with applications requiring strong toughness and resistance to thermal cracking.
1.2714
1.2714 is particularly useful for large hot forging dies where toughness and hardenability through large sections are important.
High Speed Tool Steel
High speed steels retain cutting hardness at temperatures considerably above those encountered by ordinary cold work tool steels.
M2
M2 is a general-purpose high speed steel used for:
- Drills
- Milling cutters
- Taps
- Reamers
- Broaches
- Saw blades
M42
M42 contains substantial cobalt and is selected when higher hot hardness and edge retention are required for difficult-to-machine materials.
Plastic Mould Steel Grades
Plastic mould steels are selected according to requirements including:
- Machinability
- Surface finish
- Corrosion resistance
- Toughness
- Mould size
- Production volume
Common grades include P20, 1.2312, 1.2738, 1.2316 and NAK80.
How to Choose a Tool Steel Grade
Do not start with hardness alone.
Ask five questions:
- What material will the tool process?
- Is wear, impact, heat or corrosion the dominant failure mechanism?
- What hardness is actually required?
- What is the tool size?
- What production volume is expected?
For example, a high-wear stamping die and a high-impact punch may require completely different materials even though both are technically cold work tools.
Tool Steel Purchasing Checklist
Before ordering, specify:
- Steel grade
- Governing standard
- Dimensions
- Quantity
- Delivery condition
- Required hardness
- Surface condition
- Ultrasonic testing requirement
- Machining allowance
- End application
A tool steel grades chart should therefore be used as the beginning of material selection—not as a substitute for engineering review.
FAQ
What are the main types of tool steel?
The major categories include cold work, hot work, shock-resistant, high speed and mould steels.
What is the most widely used cold work tool steel?
D2 / DIN 1.2379 is one of the most widely used high-wear cold work grades.
What is the most common hot work tool steel?
H13 / DIN 1.2344 is one of the most commonly used hot work grades.
What tool steel has the highest hardness?
Certain high speed steels such as M42 can reach very high working hardness, but hardness alone does not determine which steel is best.
