Stainless Steel 316L

Stainless Steel 316L in CNC Machining

Stainless Steel 316L is a popular austenitic stainless steel in CNC machining due to its excellent corrosion resistance, high strength, and versatility.

316L is nearly the same as 316; its lower carbon content is the only distinction. Its carbon content is typically around 0.03% to 0.035%, while 316 has 0.08% to 0.10%. Additionally, it doesn’t need post-weld annealing. This stainless steel is commonly employed in various industries, including chemical and petrochemical, food processing, pharmaceuticals, medical devices, jewelry, luxury watches (especially diver’s watches), potable water piping, wastewater treatment, marine applications, and architectural projects near the seashore or in urban areas.

While Stainless Steel 316L is generally machinable, it is considered less machinable than some other stainless steel grades. Proper tooling, cutting speeds, and feeds are important for achieving good results. We use a suitable coolant or lubricant to dissipate heat generated during machining and to improve tool life. This is particularly important due to the material’s tendency to work harden. Stainless Steel 316L exhibits good dimensional stability during and after machining. We also consider post-machining processes that may affect tolerances.

What is Stainless Steel 316L?

316L stainless steel, also known as A4 or marine grade stainless steel, is a widely used austenitic stainless steel, ranking second after 304/A2 stainless steel. Its main components are chromium (16–18%), nickel (10–12%), and molybdenum (2–3%), with small amounts of silicon, phosphorus, and sulfur.

The addition of molybdenum enhances its corrosion resistance, making it more resistant to localized corrosive attack by chlorides and general corrosion by reducing acids compared to 304. 316L is a low-carbon version of 316 stainless steel, and when cold worked, it can achieve high yield and tensile strengths similar to Duplex stainless grades.