FM ALLOY DURO-SP DURO-V5 DURO-V2 Steels for precision die Blanking punch The DURO Series is high performance steel for die that exceeds P/M high-speed steel with a balance of wear resistance and toughness 2 High wear resistance than P/M high-speed steel in high friction speed range (adhesive wear range) SP, V5 3 Superior toughness than P/M high-speed steel V2 V2 V5 Matrix High-speed steel P/M HSS Toughness 1 Toughness decrease is small even if surface roughness worsens SP, V5, V2 Better Features SP M2 D2 Wear resistance Better

Change in bending strength Shimadzu Autograph Sample: 5×10×60 mm Charpy impact testing machine Sample: 5×10×60 mm Notch: None Span: 50 mm 120 DURO-V2 DURO-V2 Charpy impact value (J/cm2) Bending strength (GPa) 6 Change in impact value DURO-V5 4 P/M HSS DURO-SP 2 80 DURO-V5 40 DURO-SP Feature 3 DURO-V2 has superior toughness 0 Ground surface Surface roughness worsening (Electro discharge machining) Ground surface Toughness decreases due to worsening of surface roughness Steel grade DURO-SP DURO-V5 DURO-V2 P/M HSS Advancement of wear Remaining tool marks 0 Rough surface due to EDM worsening Example...

Failure process Toughness Superior Toughness with condition of surface wear DURO-SP and DURO-V5 are better against wear on die 1. DURO-SP has superior wear resistance so development of unevenness due to wear is slow 2. DURO-V5 has great resistance to generation and expansion of cracks Condition after the same shot DURO-V5 2. Difference in crack generation and resistance to expansion Wear Cracking Expansion Chipping DURO-SP Based on the conditions after the same shot usage (see ), the DURO-SP has better wear resistance than P/M HSS so the wear is not as advanced (see 1 in diagram). Comparing toughness...

Heat treatment conditions Salt bath heat treatment (example of standard conditions) 1160°C 580°C A(s) AC A(s) AC AC T (min) Hot bath quenching 550°C 850°C 580°C 580°C AC 1160°C DURO-SP Until inside and outside are uniform Hot bath quenching 550°C 850°C A(s) A(s) DURO-V5 560°C 560°C AC T (min) T (min) Until inside and outside are uniform AC AC T (min) T (min) DURO-SP and DURO-V5 up to 10 mm up to 2/5 inch 80 to 190 60 Diameter or Thickness Heating time A(s) Tempering time T (min) 10 to 25 2/5 to 1 190 to 310 90 1100°C Until inside and outside are uniform Hot bath quenching 550°C 850°C 25 to 50...