Stainless steel 1.4301 or 1.4404: 304 or 316L?
1.4301 (AISI 304, V2A) is what most people mean by stainless steel. 1.4404 (AISI 316L, V4A) looks exactly the same but stands up to salt and chlorine much better. 1.4301, in turn, costs less, is available everywhere and is enough for almost everything. This guide explains when the difference matters. Up front: we cut 1.4301 from stock and 1.4404 on request only.
Side by side
| 1.4301 | 1.4404 | |
|---|---|---|
| Designation | X5CrNi18-10 | X2CrNiMo17-12-2 |
| Also known as | AISI 304, V2A | AISI 316L, V4A |
| Chromium | 17.5 to 19.5 % | 16.5 to 18.5 % |
| Nickel | 8 to 10.5 % | 10 to 13 % |
| Molybdenum | none | 2 to 2.5 % |
| Carbon | max 0.07 % | max 0.03 % |
| Against salt and chlorine | limited | much better |
| Magnetic | not as delivered | not as delivered |
| With us | from stock, 1 to 5 mm | on request |
The difference is molybdenum
Stainless steel does not rust because a thin protective layer of chromium oxide forms on it. Chlorides, meaning salts, attack that layer at single points. Small, deep holes form, which is called pitting. It happens in seawater and coastal air, with road salt, in chlorinated pool water and with some cleaning agents.
1.4404 contains 2 to 2.5 % molybdenum, which makes the protective layer much more resistant to chlorides. In everything else the two are very similar: strength, weldability and appearance barely differ.
Why we stock 1.4301
The advantage of 1.4404 only counts where salt or chlorine is involved. Everywhere else 1.4301 is the better choice: it does without expensive molybdenum, needs less nickel and so costs noticeably less.
It is also the best-selling stainless steel there is. Every stockist carries it in all common thicknesses, so we can cut it from stock and deliver quickly. In strength, weldability and appearance you will not notice a difference, and both are worked with the same tools.
When 1.4301 is enough
For almost anything that does not see salt: indoors, in the kitchen, on machines, in the garden and on a house wall inland. Rain on its own does 1.4301 no harm. House numbers, mailbox signs and nameplates do well in 1.4301.
What helps 1.4301 where there is a little salt: smooth surfaces where nothing collects, and a rinse with water now and then.
1.4404 with us
1.4404 is not in the configurator. Ask for it through the quote form, with your drawing, the thickness and the quantity. We will tell you whether we can source it and what the part costs, before anything is ordered.
Our recommendation
Indoors, kitchens, machines, nameplates
House numbers, signs and garden parts inland
1.4301. Rain is not a problem.
Boat, jetty, coast
1.4404, through the quote form. Or aluminium AlMg3, which is also seawater resistant and is in the configurator.
Near salted roads, under a car
1.4404.
Swimming pools and chlorinated water
1.4404 for parts that carry no load. Load-bearing parts in indoor pools fall under their own rules, which call for even higher-alloyed grades.
Food
1.4301 is the standard in kitchens. For very salty or acidic food, 1.4404.
For 1.4404, please use the quote form.