How to Select Cold Work Tool Steel for Blanking, Stamping and Forming Dies

Selecting cold work tool steel requires more than comparing hardness values. The correct grade must resist the specific combination of abrasive wear, adhesive wear, compressive pressure, impact, chipping and heat-treatment distortion present in the application.

A steel with maximum wear resistance may fail prematurely if the tool experiences impact. Conversely, a very tough steel may wear too quickly during long production runs.

A reliable selection process should begin with the tool’s operating conditions and expected failure mode.

What Is Cold Work Tool Steel?

Cold work tool steel is used for tools that form or cut materials at temperatures generally below their recrystallisation temperature.

Typical cold work applications include:

• Blanking
• Punching
• Stamping
• Bending
• Deep drawing
• Cold heading
• Cold extrusion
• Thread rolling
• Shearing
• Powder compaction

Cold work steel generally requires high hardness, wear resistance, compressive strength and dimensional stability. Toughness requirements vary according to tool geometry and impact load.

Start with the Tool-Failure Mode

The most effective way to select a steel grade is to identify how the existing tool fails.

Changing to a more expensive grade without identifying the cause may not solve the problem.

Factor 1: Workpiece Material

The material being processed strongly affects die wear.

Mild Carbon Steel

General stamping and forming of mild steel often requires a balanced cold work grade. A2 may be suitable when toughness and dimensional stability are important, while D2 is commonly used for longer production runs.

Stainless Steel

Stainless steel creates high friction and has a strong tendency to gall. D2, 1.2379, 1.2601 and DC53 may be considered, depending on sheet thickness, die clearance and impact load.

Lubrication, surface finish and coating selection are also important. A high-performance steel alone may not prevent adhesive wear.

High-Strength Steel

High-strength steel produces greater forming pressure and higher stress at the cutting edge. DC53 or another grade combining high compressive strength with good chipping resistance may outperform conventional high-wear steel.

Silicon Steel and Electrical Steel

Silicon steel can create severe abrasive wear during high-volume stamping. High-wear grades such as 1.2379, 1.2601 or 1.2080 may be considered, provided the tool is well supported and impact loading is controlled.

Factor 2: Sheet Thickness and Die Clearance

Thicker workpieces normally generate higher cutting forces and shock loads. A high-carbide grade with limited toughness may chip when used for thick-sheet blanking.

For thin-sheet, accurately aligned, high-volume production, wear resistance may be the dominant requirement. For thicker sheet or unstable loading, a tougher grade is usually safer.

Incorrect die clearance can cause:

• Excessive cutting force
• Burr formation
• Punch bending
• Edge chipping
• Premature cracking

Material selection should therefore be evaluated together with die clearance and tool geometry.

Factor 3: Production Volume

For short production runs, the highest-performance material may not provide an economic return. A grade with easier machining and lower total manufacturing cost may be more practical.

For long production runs, material cost represents only a small part of the total tooling cost. Tool life, maintenance intervals, downtime and part consistency become more important.

High-wear grades such as D2, D3 and 1.2601 may be justified when tools operate continuously and abrasive wear limits service life.

Factor 4: Wear Resistance vs Toughness

Wear resistance and toughness often compete with each other.

Steels containing a high volume of hard carbides generally provide excellent wear resistance. However, large or uneven carbide structures can reduce toughness and increase sensitivity to edge chipping.

A simplified selection guide is:

• 1.2080/D3: Very high abrasive wear resistance, lower impact tolerance
• 1.2379/D2: High wear resistance with moderate toughness
• 1.2601: High wear resistance, compressive strength and improved balance for demanding dies
• A2: Higher toughness and dimensional stability with moderate wear resistance
• DC53: High hardness combined with improved toughness and chipping resistance

These grades should not be selected solely according to this general ranking. Steel quality and heat treatment can significantly affect performance.

Factor 5: Tool Geometry

Thin punches, sharp corners, deep cavities and sudden section changes create stress concentration.

A highly wear-resistant but relatively brittle steel may perform well in a large, well-supported die insert but fail in a slender punch.

For complicated tool geometries:

• Use adequate corner radii
• Avoid sudden section changes
• Select a tougher steel
• Control machining marks
• Apply appropriate stress relief
• Prevent excessive hardness
• Confirm support and alignment

A2 or DC53 may be preferred when chipping resistance is more important than maximum abrasive wear resistance.

Factor 6: Heat-Treatment Stability

Heat treatment determines the final microstructure, hardness, toughness and dimensional accuracy of the tool.

Important considerations include:

• Austenitising temperature
• Holding time
• Cooling rate
• Tempering temperature
• Number of tempering cycles
• Section size
• Retained austenite
• Decarburisation protection
• Cryogenic treatment requirements

Air-hardening grades such as A2 and D2 can reduce quenching severity, but they still require precise temperature and atmosphere control.

The heat-treatment process should be based on the specific steel grade and required application. Parameters should not be copied from another grade simply because the two materials are considered similar.

Factor 7: Machining and Wire EDM

Complex dies may require extensive machining, grinding or wire EDM after hardening.

Wire EDM produces a heat-affected surface and recast layer. Improper procedures can cause microcracks and reduce fatigue life.

For EDM-processed tools:

1. Use the correct heat-treatment cycle.
2. Avoid excessive internal stress.
3. Apply multiple finishing passes.
4. Remove the affected layer when necessary.
5. Polish critical surfaces.
6. Consider stress-relief tempering.
7. Avoid sharp internal corners.

DC53 is frequently considered for EDM-intensive tooling, although D2 can also perform successfully with suitable processing.

Recommended Grades by Application

This table provides preliminary guidance only. Final selection should consider tool dimensions, target hardness, production volume and heat-treatment capability.

Information to Provide When Requesting a Quotation

To receive an accurate material recommendation and quotation, buyers should provide:

• Required steel grade or applicable standard
• Round bar, flat bar or steel plate
• Dimensions and tolerances
• Required quantity
• Annealed, pre-machined or hardened condition
• Target hardness
• Surface condition
• Ultrasonic testing requirement
• Workpiece material
• Tool application
• Expected annual production volume

When the grade is not specified, application information helps the supplier recommend an appropriate material.

The best cold work tool steel is not always the grade with the highest hardness or alloy content. The correct material is the one that addresses the dominant tool-failure mechanism at an acceptable total cost.

D3 and 1.2080 are suitable for severe abrasive wear under controlled impact. D2 and 1.2379 provide a versatile balance for long-run tooling. A2 offers greater toughness, while DC53 is useful for demanding dies requiring high hardness and improved resistance to chipping.

Huangshi Xiri supplies multiple cold work tool steel grades in steel plates, flat bars, round bars and custom sizes. Send us your application, required grade and dimensions to obtain technical support and a quotation.

FAQs

What is the best steel for stamping dies?

There is no single best grade. D2 is widely used for high-wear stamping, A2 is suitable for tools requiring greater toughness, and DC53 may be selected for high-load applications with a risk of chipping.

Which tool steel has the highest wear resistance?

High-carbon, high-chromium grades such as D3/1.2080 provide very high abrasive wear resistance. However, their lower toughness must be considered.

What hardness is required for a cold work die?

Many cold work dies operate around 58–62 HRC, but the correct hardness depends on the grade, tool geometry, loading conditions and required toughness.

Can DC53 replace D2?

DC53 can replace D2 in some applications, particularly where D2 suffers from chipping or insufficient compressive strength. Heat-treatment procedures must be adjusted because the grades are not identical.