| Analysis | Applications | Heat Treating | Tolerances | Speedy Metals items |
S7 is a shock resisting tool steel with excellent toughness and high strength, along with medium wear resistance. It has maximum shock resistance and high compression strength, which gives it good deformation resistance in use, while retaining good toughness. S7 is easy to machine in the annealed condition and can be readily heat treated. It can be quenched in air, exhibiting minimal distortion on hardening. S7 also has medium hot work characteristics, making it a versatile tool steel for both cold and warm shock applications, as well as plastic molds that require high hardness. S7 de-carb free is available in rounds, flats and squares, as well as ground flat stock and drill rod.
| Carbon (C) | Manganese (Mn) | Silicon (Si) | Chromium (Cr) | Molybdenum (Mo) | Vanadium (V) | Phosphorus (P) Max | Sulfur (S) Max |
| 0.45-0.55 | 0.2-0.8 | 0.3-1 | 3-3.5 | 1.3-1.8 | 0.2-0.3 | 0.03 | 0.03 |
A.I.S.I. S7 conforms to ASTM A681, ASTM A597
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.
FORGING
Preheat 1200°-1300°F. Forge at 2000°-2050°F. Stop at 1700°F and cool slowly.
ANNEALING
1500°-1550°F, cool slowly to 1000°F, air cool. Brinell 197 max.
PREHEATING
1200°-1300°F, prior to hardening.
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.
TEMPERING
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.
S7 de-carb free rounds are produced .015-.035 oversize. S7 de-carb free flats and squares are produced .015-.035 oversize on thickness, and widths are milled or cut oversize sufficiently to clean to nominal size.
S7 ground flat stock, produced in standard 18" and 36" lengths, is available in oversize ground (+.010/+.015" on thickness and width).
S7 drill rod (36" long standard length and 144" available) tolerances on diameter are as follows:
.124" rd and less (+/-.0003")
.125 to .499" rd (+/- .0005")
.500 to 2" rd (+/-.001")