Typical applications for S7 tool steel are punches, chisels, blanking dies, forming dies, cold and warm header dies, shears, compression dies, hobbed dies, high hardness plastic molds, zinc die casting dies, gripper dies, etc.
Preheat 1200°-1300°F. Forge at 2000°-2050°F. Stop at 1700°F and cool slowly.
1500°-1550°F, cool slowly to 1000°F, air cool. Brinell 197 max.
1200°-1300°F, prior to hardening.
1750°F. Quench in air if cross section is 2-1/2" or smaller; sections 2-1/2" to 6" should be oil quenched to black (1000°F) followed by air cooling to 150°F. Larger cross sections should be oil quenched to 150°F.
Double temper one hour per inch of section thickness to desired heating rate of 2 hours per inch. Cool in air to room temperature between the two tempers. Suggested: Cold working applications 400°-500°F. Hot working applications 900°-1000°F.
Air Cool Oil Quench Tempering Hardness Hardness Temperature F Rockwell C Rockwell C As Quenched 60 61 200 59.5 60.5 300 58.5 60 400 57 58.5 500 55.5 55.5 600 54 54 700 53.5 53.5 800 52.5 52.5 900 51.5 52 1000 50.5 51.5 1100 48 48.5 1200 37.5 37.5 1300 25.5 26.5