At Metal Supplies™ much of our Stainless Steel Box Section, Sheet, Hollow Section Tube and Flat Bar is pre-polished to various, industry-standard finishes and is available for immediate dispatch. If you’re looking for a premium stainless steel stockholder in the UK, look no further.
As one of our most popular metal products, we stock large quantities of different grades of Stainless Steel items so we can ensure your order, large or small, is dispatched immediately. For a full list of sizes for specific products, select the stainless steel section you require from the top menu. We distribute to both UK and international customers with a fast turnaround.
We also offer a first-class cutting service to suit your business or domestic needs.
For more information on our Stainless Steel supplies, please take a look at our menu options above.
If you have any questions please contact our friendly team on 0800 021 70 10.
Here are some general details about the grades and finishes our stainless supplies are available in:
For flat rolled stainless steel, standard mill finishes can achieved by either rollers or by mechanical abrasives. We first roll the steel to the chosen size and thickness, then it is annealed to change the properties of the end product. The process of pickling removes any surface oxidation, at which point the steel is ready for any final finishing you may require:
We have the different grades and surface finishes of stainless steel to suit the environment to which the material will be subjected in its lifetime.
STAINLESS STEEL FACT FOR STUDENTS!
Defined as “a steel alloy with a minimum of 11.5% chromium content by mass”, contrary to what people would understandably think, stainless steel is not 100% stain proof, but it does corrode, rust and stain less than normal untreated steel. It’s characteristic resistance to corrosion and staining, low maintenance requirements, relative good value and familiar lustre make it the ideal material for a myriad of diverse commercial uses.
This is the most widely used grade of the stainless steel. It is the most versatile as well as the most commonly stainless steel and you’ll find it in a wider range of forms, finishes and applications than any other grade.
It has a balanced, austenitic structure which enables it to be deep drawn to an incredible extent without the need for intermediary annealing.
Grade 304 stainless steel has excellent oxidation resistance in intermittent service to a temperature of 870°C and in continuous service to 925°C. Uninterrupted use of type 304 in the 425-860°C temperature range is not recommended if aqueous corrosion resistance is important for the steel’s application.
It is also very good in a vast range of different atmospheric environments and assorted corrosive media, but it is, however, subject to crevice corrosion and pitting in warm chloride environments. Stress corrosion cracking can also be an issue at temperatures above 60°C.
Heavy-welded sections in Grade 304 might require post-weld annealing for maximum corrosion resistance, but this is not a requirement when welding thin sections. It has excellent forming and welding characteristics by all standard fusion methods, with or without filler metals.
Another benefit of 304 is its excellent overall toughness, and its low temperature properties respond well to hardening by cold working.
Lastly, it is very east to fabricate and also clean.
After 304, the second most common austenitic stainless steel grade, 316 stainless has excellent toughness properties, even at ultra-low cryogenic temperatures.
It is the standard molybdenum-bearing grade, because of its excellent corrosion resistance in numerous atmospheric environments and corrosive media.
Though 316 stainless steel has a significantly higher resistance to pitting and crevice corrosion than 304, in warm chloride environments it is a problem, as is stress corrosion cracking above around 60°C.
Stainless steel in 316, like 314, has excellent forming and welding characteristics via standard fusion methods, both with and without filler metals and the requirements (or lack thereof) of post-weld for heavy welded and thin sections is the same as 314. The oxidation resistance of Grade 316 is also the same as for 314 (SEE ABOVE).
Grade 316 stainless is commonly used in the handling of particular food and pharmaceutical products where minimizing metallic contamination is an paramount.
Also known as ‘Marine Grade stainless steel’ due to its heightened resistance to chloride corrosion and saltwater corrosion resistance, it is NOT, however, resistant to warm sea water. History has shown that surface corrosion can be an issue with Grade 316 under these conditions, usually visible as brown staining.
Grade 303 stainless steel is the best for machining of the austenitic stainless steels, and represents the free machining version of Grade 304.
It is first and foremost used when extensive machining is required during production. Adding sulphur and phosphorus (responsible for the improved machining and galling characteristics) lowers the corrosion resistance of 303 stainless. Whilst it still has good resistance to mildly corrosive atmospheres it is markedly less than that of 304.
The addition of sulphur also adversely affects the weldability and formability of Grade 303 compared to 304, so it’s not suitable for work with sharp bends.
In intermittent service to 760°C and continuous service to 870°C, Grade 303 has good oxidation resistance. Due to carbide precipitation, continuous use of Grade 303 at 425-860°C is not generally recommended. 303 is susceptible to sensitisation because it doesn’t usually have a low carbon content.
Grade 303 isn’t suitable for marine-type environments. These will quickly result in pitting corrosion, and because the sulfide in Grade 303 is primarily aligned along the rolling direction the corrosion resistance is significantly reduced in cross-sections.
Though the sulphur does reduce it slightly, Grade 303 stainless steel is known for its toughness. Like other common austenitic stainless steels, it is subject to stress corrosion cracking in chloride-rich environments above temperatures of 60°C.
Grade 310 stainless is designed for high temperature service and is usually used at temperatures starting from about 800 or 900°C. It combines excellent high temperature properties with good ductility and weldability.
Grade 310 offers good oxidation resistance during intermittent service at air temperatures up to 1040°C (up to 1150°C in continuous service), providing sulphur gases aren’t present. It also has good resistance to cyclic heating and thermal fatigue.
It is used extensively where sulphur dioxide at elevated temperatures is encountered. Continuous use at 425-860°C is not recommended due to carbide precipitation.
The high chromium content in Grade 310 stainless steel, primarily included to increase high temperature resistance, also gives it fantastic corrosion resistance at normal temperatures, and when in high temperature service exhibits good resistance to oxidizing and carburising atmospheres.
Grade 310 stainless steel has similar seawater resistance to Grade 316 and resists fused nitrates up to 425°C and fuming nitric acid at room temperature.
More resistant than Grades 316 or 304, Grade 310 is subject to stress corrosion cracking.
Grade 321 is similar to304 but has a lower risk of weld decay thanks to the addition of titanium. Typically used because it is not subject to post-heating (within the carbide precipitation range of 425-850°C), inter-granular corrosion.
Grade 321 stainless is most popular for uses where the temperature range is anything up to about 900°C. It combines high strength with resistance to scaling and phase stability, particularly where subsequent aqueous corrosive conditions are present.
In the annealed condition, the corrosion resistance of Grade 321 is the same as Grade 304. It is superior to 304 stainless for welded elements that have not been post-weld annealed or if the application involves service at temperatures of 425-900°C.
By any standard fusion methods, Grade 321 stainless steel has excellent forming and welding characteristics, with and without filler metals, and no post-weld annealing is required.
Even at cryogenic temperatures, it is very tough and has good oxidation resistance: intermittent service = to up 900°C, continuous service = up to 925°C.
In the 425-900°C range, Grade 321 performs well, but is liable to stress corrosion cracking above about 60°C and to pitting and crevice corrosion in warm chloride environments.
Grade 321 does not polish well, so is not generally recommended for decorative uses.
This heat treatable, nickel-bearing grade resists scaling in intermittent service to 925°C and in continuous service to 870°C, but is generally not recommended for use in temperatures above the relevant tempering temperature, because of reduction in mechanical properties.
Grade 431 stainless has excellent resistance to a wide variety of corrosive media and reasonable resistance to salt water in cold southern waters but less resistant than Grade 316 in tropical waters. Overall the corrosion resistance of Grade 431 is approximately the same as or slightly below that of Grade 304.
Grade 431’s performance is best with a smooth surface finish, in the hardened and tempered condition. It has excellent tensile and torque strength, and good toughness, making it ideally suited to shafting and bolt applications.
In the annealed condition Grade 431 is relatively easily machined, but if hardened to above 30HRC machining becomes more difficult, however it can be hardened to approximately 40HRC.
Because of its high yield strength, Grade 431 stainless steel is not readily cold worked and is therefore not recommended for use in operations such as cold heading, bending, deep drawing or spinning. Fabrication must be by methods that allow for poor weldability due to cracking, a pre-heat of 200-300°C is recommended prior to welding and usually also allow for a final harden and temper heat treatment.
For more information, help and advice, call us today on 0845 078 0909, send us an email: Sales@MetalSupplies.com or fill in our online enquiry form on our contact page.