Stainless Steel Flats: Strength, Durability & Corrosion Resistance
Our stainless steel flat bar products are available in a huge range of imperial and metric sizes (we typically stock 8 x 5 mm to 300mm x 12mm in metric and 3/8″ x 1/8″ to 4″ x 1″ in imperial) and a variety of popular grades, including 316, 304 and 430. Most of the grades we use in our stainless flat bar products can be readily welded using the full range of conventional welding methods.
We also offer a first class cutting and polishing service and immediate dispatch to ensure a quick turnaround on your order, whether you’re a commercial or domestic customer.
To view a full list of our most commonly stocked sizes of stainless flats, please click here. Alternatively, just give us a call on 0800 123 70 10 or email with your requirements for a speedy quote.
Industrial, mechanical and structural
Stainless steel flat bars, also referred to stainless flat bar or simply stainless flats are widely used for industrial tools and mechanical parts as well as structural and construction applications. There are two methods of angle bar processing: rolled annealed and pickled (HRAP) and slit rolled edge (SRE).
Hot rolled annealed and pickled stainless flat bar if firstly rolled on a hot strip mill (hence the term ‘hot rolled’) whilst the subsequent annealing process involves heating the cooled stainless steel to alleviate stresses and ensure the highest possible resistance to corrosion – this is what makes the steel ‘stainless’ (though the annealing process does leave a scale on the surface of the stainless flats which is removed in the final pickling stage).
Pickling is a process of immersing the steel in a chemical solution that removes this scale. NOTE: though stainless steel flat bar rarely stains, corrodes, or rusts as other types of steel might, but this doesn’t mean that stainless flat bars are completely stain proof.
Corrosion-resistant steel
Stainless steel flat bar is sometimes also known as corrosion-resistant steel when an alloy grade or type isn’t specified (most often in the aviation industry). There are many different surface finishes available for flat, each designed to suit the particular conditions that it will be subject to during its lifetime.
Stainless steel flat bar differs from mild steel (or carbon steel) flat bar as carbon steel rusts when exposed directly to moisture. This rust is highly active and will increase corrosion by producing more rust, an endless cycle which will eventually consume the surface of the metal. Stainless flat bars have enough chromium to produce a passive film of chromium oxide that will prevent surface damaging corrosion and any corrosion of the metal’s internal structure.
Different types:
Ferritic stainless steel flat bar
- Commonly contain a minimum of about 11% chromium
- Typically inexpensive as they don’t contain a trace of nickel
- Magnetic
Austenitic stainless steel flat bar
- 18% of chromium content and 8% nickel
- Non-magnetic, advantageous for marine applications where magnetism will confuse compass and direction finding tools
- Improved formability over ferritic stainless steels and superior at maintaining strength under high temperatures
- Less that 2% molybdenum meaning corrosion resistance is drastically improved
Martensitic stainless steel flat bar
- 11.5% chromium and typically no nickel content
- Around 0.15% – 0.4% carbon content
- Extremely high strength in the hardened condition
- Tempering at 150°C to 170°C increases corrosion resistance
- Well known for abrasion and wear resistance
