Tool Steel Selection by Failure Mode

High Compressive Strength Tool Steels for Plastic Deformation Resistance

In the plastic deformation failure mode, the working edge, forming surface, punch head, die corner, or cavity area yields under load. The tool may still look intact, but its geometry has changed, making it difficult to control part accuracy, clearance, and forming stability.

Tool Steels Available for Plastic Deformation Resistance

Aobo Steel supplies cold work, hot work, and high-speed tool steels for high-pressure dies, punches, forming tools, extrusion tooling, and applications where edge collapse or surface sinking must be controlled.

D2 | 1.2379 | SKD11

High-pressure cold work steel for wear resistance, edge stability, and deformation resistance.

D6 | 1.2436 | SKD2

Cold work grade for severe wear and pressure conditions where impact risk is controlled.

A2 | 1.2363 | SKD12

Balanced cold work steel when deformation resistance must be combined with better toughness.

Acero para herramientas Cr12MoV

GB cold work grade for general dies, forming tools, cutting tools, and pressure-resistant cold work applications.

O1 | 1.2510 | SKS3

Oil-hardening cold work steel for moderate-load tools, smaller dies, and shorter production runs.

M2 | 1.3343 | SKH51

High-speed steel for cold extrusion punches, cutting tools, and high-pressure special tools.

To reduce this failure, high-compressive-strength tool steels such as D2, D3, D6, A2, and Cr12MoV are selected for cold work applications requiring high hardness, compressive strength, and resistance to surface collapse or edge rounding.

When the same deformation problem arises at elevated temperatures, H11 and H13 are chosen. In hot forging, die casting, hot extrusion, or hot shearing, the steel must simultaneously resist both pressure and softening.

In actual tooling, plastic deformation usually appears as edge rounding, surface sinking, punch mushrooming, die corner collapse, cavity distortion, or unstable clearance. This failure is different from normal abrasive wear because the tool is not only losing material but also changing its working geometry.

Plastic deformation results from low hardness, insufficient compressive or hot strength, or excessive pressure. If chipping or cracking occurs first, toughness, not hardness, may be needed.

Recommended High-Compressive-Strength Tool Steels

Grade / GroupCalificaciones equivalentesBest Use DirectionLimitación
D21.2379 / SKD11 / Cr12Mo1V1High-pressure cold work tools needing wear resistance and deformation resistanceNot suitable for heavy impact
D31.2080 / SKD1High-hardness cold work tools under steady pressureLower toughness than D2
D61.2436 / SKD2Severe wear and pressure conditionsImpact risk must be controlled
A21.2363 / SKD12Tools needing better toughness than D2 while still resisting deformationLower wear resistance than D2 and D3
Cr12MoVChinese GB gradeGeneral cold work dies, forming tools, and cutting toolsPerformance depends strongly on heat treatment
O1 / O21.2510 / 1.2842Moderate-load tools, smaller dies, and shorter production runsNot suitable for severe pressure
H111.2343 / SKD6Hot work tools needing pressure resistance and toughnessNot a cold work wear steel
H131.2344 / SKD61Hot forging, die casting, hot extrusion, and hot shear toolsLower cold wear resistance than D-series steels
M2 / M4High-speed steelsCold extrusion punches, cutting tools, and high-pressure special toolsHigher cost and more specific use
PM Tool SteelsPM cold work and PM high-speed gradesVery high hardness with improved carbide uniformityMayor costo
Cemented CarbideWC-Co gradesExtreme compressive load beyond tool steel capabilityPoor tolerance for bending and impact

D2 is usually the practical starting point for cold work deformation resistance. D3 and D6 move further toward wear and pressure resistance. A2 is useful when the tool also needs more toughness.

Cemented carbide is used only when tool steel cannot carry the pressure. Its room-temperature compressive strength ranges from 3,450 to 6,900 MPa, but it is much less tolerant of bending, impact, or poor support.

How to Choose Tool Steel for Plastic Deformation Resistance

Condiciones de funcionamientoMejor dirección de los materiales
Cold work pressure with wearD2 / D3 / D6 / Cr12MoV
Cold work pressure with chipping riskA2 or lower-hardness D2 direction
Moderate pressure and lower production volumeO1 / O2
Hot pressure above about 200 CH11 / H13
Severe cold extrusion or high-load punchingM2 / M4 / PM tool steel
Pressure exceeds steel capabilityCemented carbide or tool redesign

For cold extrusion, practical pressure limits are useful. Punch pressure is often kept below about 2,370 MPa, and die internal pressure below about 1,895 MPa. When the working pressure approaches these levels, grade selection should be checked together with tool geometry, backing support, and contact area.

PM steels are useful when conventional high-alloy steels cannot provide sufficient hardness and toughness simultaneously. Some PM grades can reach about 64-69 HRC while keeping a finer carbide structure than conventionally produced steels.

Common Applications of High Compressive Strength Tool Steels

AplicaciónDirección de grado comúnRequisito principal
Blanking punches and diesD2 / D3 / D6 / Cr12MoVEdge stability and wear resistance
Herramientas de acuñaciónD2 / D6 / M2Resistance to surface sinking
Peines de laminado de roscasD2 / M2 / PM steelsPressure resistance and dimensional stability
Punzones de extrusión en fríoD2 / M2 / M4 / PM steelsHigh compressive strength with controlled toughness
Matrices de embutición profundaD2 / A2 / Cr12MoVStable die geometry
Cold heading toolsD2 / A2 / M2Compression resistance with toughness
Powder compaction diesD2 / D6 / PM steels / carbideHigh pressure and abrasive wear resistance
Rollos formadoresD2 / D6 / Cr12MoVSurface stability and wear resistance
Matrices de forja en calienteH11 / H13Resistencia al calor y a la fatiga térmica
matrices de fundición a presiónH13 / H11Heat resistance and pressure resistance
Hot extrusion toolsH11 / H13 / H21 directionHot compressive strength

When High Compressive Strength Is Not Enough

ProblemaSignificado de la selección
Cracking or chipping firstHigh compressive strength is ineffective if cracking or chipping occurs before deformation. In such cases, A2, S7, or lower-hardness steels may prolong tool life compared to hard D-series steels.
Pressure with heatD2, D3, D6, and Cr12MoV can resist cold pressure, but they lose strength as the temperature rises. H11 and H13 are better choices when high-temperature hot working is combined with pressure.
Local overloadIf the tool still deforms after correct material selection and heat treatment, the load may be too concentrated for the working area. This usually requires better backing support, a larger contact area, improved radius design, or a material upgrade to PM steel or cemented carbide.

Need Tool Steel for High-Pressure Dies or Forming Tools?

Aobo Steel supplies tool steel round bar and flat bar for high-pressure dies, forming tools, extrusion punches, and hot work applications. Send your required grade, size, quantity, and application.

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