When speaking about Stainless Steel in Piping, the most common grades are: Stainless Steel 304/304L & 316/316L.
What is the difference between both grades?
*For 304/304L & 316/316L: they are categorized under: “Austenitic Stainless Steels” group.
– The type 304 austenitic stainless steel contains 18–20% Cr and 8–12% Ni and is often referred to as ‘‘18–8’’ stainless steel for the chromium and nickel content.
– The type 316 austenitic stainless steel contains: 17% Cr, 11% Ni, 2% Mo), the Mo addition results in higher corrosion resistance.
So, what is “L” in 304L and 316L?
* L means: Low Carbon.
– 304L Lower carbon than 304 for improved corrosion resistance.
– 316L Lower C for improved corrosion resistance and weldability.
—
Other Non common Grades from 304 and 316:
– 304LN Low-carbon 304 with nitrogen added for strength
– 304H Higher carbon 304
– 304Cu Copper added for improved cold working
– 304N Nitrogen added for strength
– 316LN Lower C and higher nitrogen (for strength)
– 316H Higher carbon 316
– 316N Nitrogen added for strength
– 316Ti Titanium added
– 316Cb Niobium (columbium) added
—
Reference: Handbook of Materials Selection, MYER KUTZ.