Stainless Steel

Stainless steel is an alloy of Iron with a minimum of 10.5% Chromium. Chromium produces a thin layer of oxide on the surface. This prevents any further corrosion of the surface. Increasing the amount of Chromium gives increased corrosion resistance levels.

Stainless steel also contains varying amounts of Carbon, Silicon and Manganese. Other elements such as Nickel and Molybdenum may be added to impart other useful properties such as increased corrosion resistance or easier formability.

We can supply grades in all forms such as:

·         Sheet

·         Mesh

·         Plate

·         Bar

·         Tube

·         Angle

·         Flat

·         Profiles

Grades

300 Series—austenitic chromium-nickel alloys

301Highly ductile, for formed products. Also hardens rapidly during mechanical working. Good weldability. Better wear resistance and fatigue strength than 304.

302Same corrosion resistance as 304, with slightly higher strength due to additional carbon.

303Free machining version of 304 via addition of sulphur and phosphorus.

304 

The most common grade; the classic 18/8 (18% chromium, 8% nickel) stainless steel.

304LSame as the 304 grade but lower carbon content to increase weldability. Is slightly weaker than 304.

304LNSame as 304L, but also nitrogen is added to obtain a much higher yield and tensile strength than 304L.

308Used as the filler metal when welding 304.

309Better temperature resistance than 304, also sometimes used as filler metal when welding dissimilar steels, along with Inconel.

316

The second most common grade (after 304); for food and surgical uses. The addition of molybdenum prevents specific forms of corrosion. It is also known as marine grade stainless steel due to its increased resistance to chloride corrosion compared to 304..

316LA extra low carbon grade of 316, generally used in stainless steel watches and marine applications, as well exclusively in the fabrication of pressure vessels due to its high resistance to corrosion.

321Similar to 304 but contains a lower risk of weld decay due to addition of titanium.

400 Series—ferritic and martensitic chromium alloys

405Ferritic for welding applications

408Heat-resistant; poor corrosion resistance; 11% chromium, 8% nickel.

409Cheapest type; used in the automobile industry for exhausts etc.

410Martensitic (high-strength iron/chromium). Wear-resistant, but less corrosion-resistant.

416Easy to machine due to additional sulfur

420Cutlery Grade martensitic.

430Decorative, e.g., for automotive trim; ferritic. Good formability, but with reduced temperature and corrosion resistance.

439Ferritic grade, a higher grade version of 409 used for catalytic converter exhaust sections. Increased chromium for improved high temperature corrosion/oxidation resistance.

440A higher grade of cutlery steel, with more carbon, allowing for much better edge retention when properly heat-treated. Due to its toughness and relatively low cost, most display-only and replica swords or knives are made of 440 stainless. Available in four grades:

·         440A—has the least amount of carbon making this the most stain-resistant.

·         440B—slightly more carbon than 440A.

·         440C—has the greatest amount of carbon of the Type 440 variants. Strongest and considered more desirable in knifemaking. This variant is also more readily available than other variants of Type 440.

·         440F—a free-machining variant. Contains the same high carbon content as Type 440C.

446For elevated temperature service