Material grade
304
Grade of Stainless Steel. Grades are not interchangeable.
Stainless steel 304 is the common austenitic 18-8 grade, often aligned with EN 1.4301. It is used for machined fittings, brackets, enclosures and general corrosion-resistant hardware. 304L, the low-carbon variant, is a separate grade on Metraxio and is the usual choice when the part is welded and sensitization matters.
Grade overview
304 resists many indoor and mild outdoor environments. It is not the default for chloride-rich or marine duties, where buyers more often look at 316. It work-hardens in machining and can distort in welding. Sheet, plate, bar and tube are different product forms and should be named. Metraxio does not print hardness or strength tables here, because those depend on the product standard and the condition.
Typical manufacturing routes
CNC turning and milling, laser cutting, press-brake forming and TIG or MIG welding are all common, and they are separate capabilities. A machined 304 fitting and a welded 304 tank are not the same project. Passivation or a polished finish is a surface-treatment step to specify when the application needs it.
Machinability and process constraints
304 is machinable and widely used, and it is less free-cutting than 303. Threads, thin walls and small tools need a shop that is used to austenitic stainless rather than to aluminum. 303 can be proposed for a turned part that is not welded, but only if you accept the lower corrosion resistance and say so. 303 and 304L are separate grades.
Typical applications
Typical parts are food-equipment brackets that do not need a more alloyed grade, machine covers, fasteners, manifolds and general industrial hardware. Hygienic or chemical duties may need a stated surface finish and a certificate. 304 on a drawing is not by itself a hygienic specification.
What to include in the manufacturing project
Write 304 or 1.4301, the product form, the standard if one applies, the quantity, the finish and whether the part is welded. If welding is in scope, consider whether the requirement should be 304L. Ask for a material certificate when traceability is part of the order.
Buyer questions
304 or 304L?
Use 304L when the part is welded and you need to limit sensitization. For a machined part with no weld, 304 is the usual callout. They are different grades on Metraxio.
304 or 316?
316 is the usual step up for chlorides and many chemical duties. It costs more and machines differently. Change the grade only when the service needs it.
Why does 304 feel harder to machine than aluminum?
Austenitic stainless work-hardens and needs different tools and feeds. That is a process constraint, not a reason to drop the grade without agreement.
Does the page offer 304 from stock?
No. Specify the grade in a manufacturing project. Sourcing covers availability after the requirement is known.