304 Stainless Steel
Type 304 stainless is perhaps the most commonly referenced stainless steel.
It is a general purpose stainless steel grade with a wide range of applications in construction and engineering.
It is an alloy of 18% Chromium, 8% Nickel, austenitic stainless steel. Sometimes written as 18/8.
|304||1.4301||Type 304||UNS S30400|
|304 L||1.4307||Type 304L||UNS S30403|
Widely available as:
- Sheet – 0.5mm-3mm thick
- Plate – 3mm-15mm thick
- Heavy plate – 20mm and above
- Tube, pipe, castings
- hot rolled angle
- hot rolled channel section.
|3mm||20 x 20||25 x 25||30 x 30||40 x 40||50 x 50|
|5mm||25 x 25||30 x 30||40 x 40||50 x 50||60 x 60|
|6mm||25 x 25||30 x 30||40 x 40||50 x 50||60 x 60||70 x 70||75 x 75||80 x 80||100 x100|
|10mm||50 x 50||60 x 60||70 x 70||80 x 80||100 x 100|
All other angle sizes can be sheared from plate and cold formed by CNC pressbrake.
|3mm||30 x 30 mm||Up to||300 x 300 mm||3000mm long|
|4mm||40 x 40 mm||Up to||300 x 300 mm||3000mm long|
|5mm||50 x 50 mm||Up to||300 x 300 mm||3000mm long|
|6mm||60 x 60 mm||Up to||300 x 300 mm||3000mm long|
|8mm||75 x 75 mm||Up to||300 x 300 mm||3000mm long|
|10mm||90 x 90 mm||Up to||300 x 300 mm||3000mm long|
|12mm||120 x 120 mm||Up to||300 x 300 mm||2500mm long|
|15mm||150 x 150 mm||Up to||300 x 300 mm||1500mm long|
Other combinations of unequal leg lengths are also possible, see Cold Forming
Irregular shaped pieces and curved shapes can be cut by plasma, laser or waterjet. The cutting process selection depends on the thickness of the material and the quality and profile of the finished cut edge. See Plasma Cutting
Holes can be drilled or milled. See Holes & Slots
Slotted holes can be punched or milled. See Holes & Slots
304 stainless can be welded with MMA, MIG or TIG welding. Grade 304L for welding. 304L has a lower carbon content, which prevents precipitation of complex Cr Carbides at the grain boundaries in the heat affected zone (sensitisation). The majority of plate and sections are currently double certified as 304/304L, but check. For more about welding
There are a range of surface finishes available for stainless steel see polishing
Typical Mechanical Properties
(Note - these are indicative guideline values- not to be used for design – check with appropriate standard)
|0.2% proof stress||N/mm2||200-230|
See BS EN ISO 10088-2