Stainless Steel 416

Stainless Steel 416 is the most easily machinable of all stainless steel grades, making it the default choice when high-volume precision machining is required. As a martensitic (ferromagnetic) stainless, it differs fundamentally from the austenitic 300-series grades: it can be hardened by heat treatment to HRC 45–52, providing a unique combination of free-machining convenience and usable strength. The addition of sulfur (0.15% minimum) forms MnS inclusions that act as internal chip breakers, while the martensitic microstructure is inherently more machinable than austenite. Machinability is comparable to standard carbon steels (like 1214 or 1144), making 416 an excellent "stainless alternative" for applications requiring corrosion resistance with maximum machinability. Its magnetic properties (in all conditions) and limited corrosion resistance compared to 304/316 restrict it to applications where these characteristics are acceptable.
 

Mechanical Properties

• Density: 7.75 g/cm³
• Tensile Strength: 655 MPa
• Yield Strength: 275 MPa
• Elongation at Break: 28%
• Reduction of Area: 45%
• Hardness: HRC 24–34 (annealed); HRC 45–52 (heat-treated)
• Modulus of Elasticity: 200 GPa
• Thermal Conductivity: 24.9 W/m·K
• Melting Point: 1427–1510 °C
• Coefficient of Thermal Expansion: 9.9 × 10⁻⁶ /°C

Advantages

✔  Easiest-to-machine stainless steel grade — machinability comparable to free-machining carbon steels (1214/1144 level)

✔ Higher thermal conductivity (24.9 W/m·K) than austenitic grades — cooler cutting zone, reduced thermal tool wear, and better dimensional control

✔ Lower coefficient of thermal expansion (9.9 × 10⁻⁶/°C) — superior dimensional stability during machining and in service

✔ Heat treatable to HRC 45–52 — achieves usable hardness and wear resistance that austenitic grades cannot match

✔ Magnetic in all conditions — useful for magnetic clamping in fixtures and magnetic sensor applications

Machining & Manufacturing

Common Applications