Stainless Steel Applications by Industry
Stainless is chosen twice: once for the grade, once for the finish. The grade that survives a chemical line will stain on a coastal facade, and a finish written as "mirror" is not the same as one written as a measurable Ra. Specify by what the part has to survive.
Three industries, and the grade each one settles on
Chemical & Process
Chemical service is a corrosion problem before it is a piping problem. The fluid decides the grade: chlorides push you from 304 to 316L, and from 316L to 2205 duplex once temperature and stress join in.
316L · 2205 · 304
ASTM A312 (pipe) · ASTM A182 (fittings) · ASTM A790 (duplex pipe) · EN 10216-5
Food & Beverage
Food contact is a surface problem before it is a material problem. The grade is usually 304 or 316L; what actually decides whether a surface is cleanable is the Ra finish, the weld quality and the passivation, not the alloy number.
304 · 316L
ASTM A240 (sheet) · ASTM A270 (sanitary tube) · 3-A · EHEDG · FDA food contact
Architecture & Facade
Architectural stainless is chosen for a finish that stays put for decades. The decision is two-part: 304 for inland, 316L for coastal or de-icing-salt exposure, and a finish — 2B, No.4, hairline or 8K — that is specified as a measurable surface, not as "shiny".
316L · 304
ASTM A240 (sheet) · ASTM A554 (welded tube) · EN 10088-2 · AAMA 2605 (coating, where applicable)
Why the grade comes second
The Same Alloy Is Two Different Products in Two Industries
316L is a chemical pipe in one order and a food-contact surface in another. The alloy is identical; what differs is the surface finish, the weld procedure and the certificate behind it. Tell us the end use and we set the inspection to match — checking a facade panel for a food-contact Ra is wasted effort, and shipping a sanitary tube without a finish spec is a rejected container.