MAXEL® 3-1/2 (Brake Die) Free-Machining Alloy Steel (AISI 4150 S)

MAXEL 3-1/2 free-machining alloy steel provides a good combination of heat treated properties and machinability. This alloy steel is manufactured under close quality control to an ASTM grain size of 5 to 8. It is suitable for service applications where strength, toughness, and hardness are required. MAXEL 3-1/2 can be supplied in the heat treated and stress relieved condition to a hardness of BHN 269/321. This results in not only an economic advantage, but also minimizes distortion normally encountered in heat treating finished parts.

Typical Chemistry Carbon 0.50% Manganese 1.25% Silicon 0.25% Chromium 0.65% Molybdenum 0.15% Sulfur 0.08%

Typical Applications Arbors Machinery Parts Bolts and Studs Shafts Boring Bars Spindles Gears Vice Jaws

Annealed Hardness: BHN 170/212. Machinability in the annealed condition is approximately 90% of W1 Tool Steel (1%C); and 70% in the heat treated condition (BHN 300). Thermal Treatments Critical Temperature: 1360F (740C).

Forging: 2100F (1150C) Do not forge below 1650F (900C). Slow cool after forging. Normalizing: 1650F (900C), equalize and air cool. Annealing: 1550F (845C), hold 2 hours, slow cool 50F(10C)/ hr max. to 1200F (650C), then air or furnace cool. Hardness BHN 170/212. Stress Relieving: Prehardened Material: 1000F(540C), hold 2 hrs, air cool. Annealed Material: 1100-1300F (595-740C), hold 2 hrs, air cool. Re-hardened Material: 50-100°F(10-38C) below last tempering temperature, hold 2 hrs, air cool. Straightening: Best done warm 400-800F (204-425C) Hardening: (Atmosphere or Vacuum Furnace) Preheat: 1300-1350F (705-730C), equalize. High Heat: 1525-1575F (830-860C), soak 10 to 30 minutes. Quench: Oil quench to below 200F (95C). Large or complicated sections may be quenched to about 350F (180C), followed by air cooling to 250F (120C). Temper immediately. Temper: Tempering at 900-1300F (480-705C) for 1 hour per inch (25mm) of thickness at temperature is recommended (2 hrs min). Note: Maxel 3-1/2 can also be selectively hardened by standard flame or induction hardening practices. Physical Properties Modulus of Elasticity ..................................................29 psi x 106(200 GPa) Specific Gravity ...........................................................................................7.80 Density ......................................................................0.282 lb/in3(7810 kg/m3) Coefficient of Thermal Expansion

Temperature Range Coefficient of Thermal Expansion °F °C in/in/°Fx10-6 mm/mm/°Cx10-6 70-200 21- 95 6.5 11.7 70-400 21-205 7.0 12.6

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