How to Extend Mold Lifespan?

What Exactly Is Mold Lifespan?

• Abnormal failure (early failure): The mold stops working before reaching the industry-recognized lifespan, often due to plastic deformation, fracture, or localized severe wear.
• Normal failure: The mold wears out after mass production, caused by gradual deformation, uniform wear, or fatigue fracture.

10 Key Tips to Extend Mold Lifespan

1. Rational Mold Structure Design: Ensure Even Stress Distribution

• Equip key parts (e.g., punches, dies) with precise guiding systems, especially small-hole punches, to resist bending and uneven wear.
• Reinforce weak areas (small holes, angles, narrow slots) and use rounded transitions (R=3-5mm) to reduce stress concentration.
• Choose interlocking structures for complex dies instead of integral designs to avoid cracking at concave corners.
• Set reasonable blanking clearances to reduce forming force and edge wear, and ensure proper fillet radii (R) for punches/dies to prevent cracks.
• Use a rigid die set (base thickness ≥45mm) and floating die shanks to maintain guiding accuracy, and install four guide pillars for progressive dies to avoid collisions.

2. Choose the Right Mold Material: Match Performance to Needs

• Prioritize high-quality steel with high hardness (58~64HRC), wear resistance, toughness, and good processability.
• Select materials based on production volume: Use long-life options (cemented carbide, SKD11, DC53) for mass production; cost-effective materials (45#, Cr12) for small batches; and high-strength, tough materials (DF-2) for deformation-prone molds.
• Ensure material quality through inspections (chemical composition, ultrasonic testing) to avoid internal defects like segregation or impurities.
• Improve carbide uniformity via forging—this can double the lifespan of Cr12 steel molds.

3. Optimize Heat Treatment: Avoid Common Pitfalls

• Use appropriate quenching temperatures: Higher temperatures for thin-walled cavities to prevent expansion; low-quenching, high-tempering for high-speed steel to boost toughness.
• Apply surface strengthening treatments like low-temperature nitrocarburizing (hardness up to 1200HV) or electrolytic sulfurizing to reduce friction.
• Temper immediately after quenching to eliminate residual stress—tempering carbon tool steel at 200℃ for 2 hours removes 75-80% of stress.
• Cool slowly after tempering (to 100-120℃) or add a second low-temperature tempering to avoid new tensile stress.

4. Strengthen Mold Surfaces: Boost Wear Resistance

• Gas nitriding: Forms a hard layer (HV950-1200) with good red hardness and anti-galling ability.
• Ion nitriding: Uses glow discharge to create a wear-resistant nitrided layer in a vacuum environment.
• Laser surface strengthening: Increases hardness by 15-20% with fine grain structure and energy efficiency.
• CVD/PVD coating: Deposits titanium carbide or nitride layers for extreme wear resistance.

5. Eliminate Wire EDM Stress: Prevent Microcracks

• Shot peening + low-temperature tempering: Converts tensile stress to compressive stress, extending life by 10-20 times (tested to 220,000 cycles for Cr12MoV molds).
• Grinding + low-temperature aging: Remove the white layer and high-hardness layer, then temper at 120-180℃ for 4-10 hours to double lifespan.
• Avoid direct use after wire EDM—even simple tempering (160℃ for 2 hours) improves life from 10,742 to 11,180 cycles.

6. Precision Machining: Reduce Surface Defects

• Control surface roughness: Ra < 3.2μm for rough machining; Ra=0.4～0.8μm for finished molds to ease demolding and reduce friction.
• Avoid sharp tool edges—round tool ends (R) and polish surfaces to eliminate stress concentration points.
• Use wet grinding with small depths (0.005-0.01mm) to prevent microcracks; avoid dry grinding for Cr12MoV steel.
• Reserve reasonable machining allowances and ensure assembly accuracy (parallelism, perpendicularity) to prevent uneven loading.

7. Select Quality Stamping Materials: Minimize Mold Stress

• Choose materials with good stamping processability to reduce forming force.
• Inspect raw materials for thickness tolerance, surface quality (no rust/oil stains), and remove oxides before stamping.
• Perform softening treatment for hard materials and use appropriate lubricants to reduce friction.

8. Ensure Proper Lubrication: Control Operating Temperature

• Use lubricants to prevent adhesive wear (most severe at 250-300℃) and cool the mold.
• Match lubricants to the stamping process and material to avoid sticking and overheating.

9. Choose Suitable Stamping Equipment: Reduce Impact

• Use high-precision, rigid presses—Cr12MoV silicon steel dies last 60,000-120,000 cycles on precision presses vs. 10,000-30,000 on ordinary presses.
• Install guide sleeves for slides to reduce clearance (0.0015 inches) and extend die life by 30%.
• Reduce slide speed at the end of the stroke to lower impact force—this cuts contact speed by 40% compared to crank presses.
• Avoid excessive stamping speed, which concentrates impact energy and causes fracture or deformation.

10. Routine Maintenance & Sharpening: Extend Service Life

• Implement the "three-inspection system": Check before, during, and after use; keep molds clean and well-lubricated.
• Control punch penetration depth and upper die stop points to avoid overloading.
• Sharpen punches/dies regularly—reducing surface roughness by 1 level doubles lifespan. Grind side faces first, then end faces, and polish to remove tool marks.

Trust Elite Mold Tech for Long-Lasting Molds

• Email: contact@elitemoldtech.com
• WhatsApp: +86 19860504405