Choosing the right stainless steel grade is the single most important decision in any bar or wire-rod purchase. This guide explains how to select special stainless steel long products by corrosion environment, service temperature, mechanical strength and weldability, with the common grades we supply as reference points. Final grade and composition should always be confirmed against the Mill Test Certificate for your project.
Most atmospheric and fresh-water services are served by austenitic 304/304L. For chloride-containing, coastal or chemical environments, 316L (molybdenum-bearing) or duplex grades give markedly better pitting resistance. For strong acids, high chlorides or seawater, move to super-austenitic (904L) or super-duplex.
Austenitic grades keep useful strength and oxidation resistance from cryogenic up to about 800°C. Ferritic and martensitic grades are preferred where high hardness or moderate temperature suffice. For high-temperature strength (bolting, valves), precipitation-hardening or specific heat-resistant grades are used.
When the design is strength-driven (shafts, fasteners, structural members), consider duplex 2205 (roughly double the yield of 316L) or precipitation-hardening grades. For free-machining components, our free-cutting stainless series reduces cycle time.
Austenitic and duplex grades weld well with proper procedure. Our welding-grade stainless wire (ER307 / ER308 / ER316 series, etc.) is formulated for stable arcs and corrosion-resistant welds. Low-carbon "L" versions minimise carbide precipitation in the heat-affected zone.
| Need | Typical grade | Common use |
|---|---|---|
| General purpose | 304 / 304L | Fasteners, shafts, fittings |
| Corrosion resistance | 316L | Chemical, marine hardware |
| High strength + corrosion | Duplex 2205 | Desalination, pressure parts |
| Welding wire | ER307 / ER316 | Welded structures |
| Soft-magnetic | Custom solenoid grade | Valves, solenoids |