International tool steel purchasing frequently involves several designation systems.

A US drawing may specify AISI H13. A European buyer may call for DIN 1.2344. A Japanese specification may reference SKD61, while a Chinese project may use 4Cr5MoSiV1.

These designations are commonly treated as corresponding grades, but buyers should understand one important rule:

Equivalent does not always mean identical.

Common Tool Steel Equivalent Grades Chart

The table above is intended as a purchasing reference. Final substitution should be based on the applicable standard and required chemistry, hardness and properties.

Why Steel Equivalents Can Cause Problems

A common purchasing mistake is assuming:

Same application = same steel.

Different standards may specify slightly different ranges for:

• Carbon
• Chromium
• Molybdenum
• Vanadium
• Silicon
• Sulphur
• Phosphorus

These differences can influence hardenability, toughness, wear resistance and heat-treatment response.

Example: H13 and 1.2344

AISI H13, DIN 1.2344 and JIS SKD61 are widely treated as corresponding hot work tool steels.

They are frequently used in:

• Aluminium die casting
• Magnesium die casting
• Hot extrusion
• Hot forging
• Hot punches

However, a purchasing specification should still identify the required standard.

Do not simply write:

H13 equivalent

when the customer’s drawing actually requires a specific DIN, ASTM/AISI or JIS chemistry.

Example: D2 and 1.2379

D2 and 1.2379 are widely cross-referenced.

Typical applications include:

• Stamping dies
• Blanking dies
• Cutting tools
• Forming dies
• Shear blades

But heat-treatment history, carbide distribution and metallurgical quality can create meaningful differences even between materials nominally meeting the same grade.

P20 Requires Extra Attention

Plastic mould steel creates greater confusion because “P20” is frequently used commercially as a family description.

Depending on the project, buyers may encounter:

• P20
• 1.2311
• 1.2312
• P20+S
• P20+Ni
• 1.2738
• 3Cr2Mo
• 3Cr2NiMo

These materials should not automatically be treated as identical.

1.2312, for example, is designed with improved machinability, while 1.2738 is commonly selected for large moulds requiring improved toughness and through-section performance.

How to Substitute Tool Steel Correctly

Before approving an equivalent grade, compare:

1. Chemical Composition

Check the actual range specified by both standards.

2. Delivery Condition

Is the material:

• Annealed?
• Pre-hardened?
• Quenched and tempered?
• ESR remelted?

3. Hardness

Verify whether hardness refers to delivery condition or final heat-treated condition.

4. Dimensions

Section size can influence achievable properties.

5. Application

A substitution that works in a general fixture may not be acceptable for a high-cycle precision die.

What to Put on an RFQ

Instead of:

“Need D2 equivalent.”

Use:

“DIN 1.2379 / AISI D2 acceptable subject to chemical composition confirmation, annealed condition, required dimensions XX × XX × XX mm, UT required.”

That simple change greatly reduces misunderstanding.

FAQ

Is DIN 1.2379 the same as D2?

They are commonly treated as corresponding grades, but buyers should verify the applicable standard before substitution.

What is the DIN equivalent of H13?

DIN 1.2344 is commonly associated with AISI H13.

What is the JIS equivalent of H13?

JIS SKD61 is commonly cross-referenced with H13.

Are P20 and 1.2738 the same?

No. They belong to the broader plastic mould steel family but have different compositions and application strengths.