The short answer on 304 vs 316 stainless steel scrap: 316 contains molybdenum, and 304 doesn’t, and that, along with a little more nickel, is what separates the higher-value grade from the everyday one. The catch is that you can’t see it, and a magnet won’t help, because both grades are normally non-magnetic.
If you’ve got a pile of stainless from a renovation, a commercial kitchen or a workshop clean-out, it pays to know roughly which grade is which before you load the ute. This guide covers how the two grades differ, what you can check yourself, what a recycler can check that you can’t, and how to present your stainless so it’s assessed properly.
Both are austenitic stainless steels from the 300 series. Both rely on chromium to resist rust and on nickel to keep the steel tough and easy to form. The practical difference is molybdenum: 316 carries roughly 2 to 3 per cent of it, while molybdenum isn’t a specified addition in 304.
That molybdenum is why 316 copes better with salt and chlorides, and why it costs more to make. Resources Victoria, part of the Victorian Government, notes that molybdenum is used as an alloying element in stainless steel, where it improves resistance to corrosion. Nickel does a different job, and Geoscience Australia lists it among the metals added to iron to make stainless steel.
|
Property |
304 |
316 |
|
Chromium (usual specification range) |
18 – 20% |
16 – 18% |
|
Nickel |
8 – 10.5% |
10 – 14% |
|
Molybdenum |
Not specified |
2 – 3% |
|
Magnet |
Normally no pull; can be weakly magnetic when bent, formed or welded |
Same |
|
Often found in |
Sinks, benchtops, cookware, food-prep equipment |
Marine and coastal fittings, chemical and pharmaceutical equipment, some food processing |
|
Scrap value |
Generally lower |
Generally higher |
Those are the usual specification limits, and real pieces vary a little. You’ll also see 304L and 316L. The L means low carbon, which helps with welding, but the alloy character is the same, so 316L still contains molybdenum.
Not by looking. Both come out the same silvery grey and take the same finishes, so appearance tells you very little. What does help falls into three steps, roughly in order of reliability.
Plates, flanges, the underside of a sink and the heads of bolts sometimes carry a grade mark such as 304, 316 or 316L. On stainless fasteners, A2 usually means 304-type and A4 means 316-type.
Cutlery and cookware often say 18/8 or 18/10, but those figures describe chromium and nickel only. They say nothing about molybdenum, so they don’t prove an item is 316.
A bench out of a commercial kitchen is most likely 304. Boat fittings, handrails near the water and equipment from chemical or pharmaceutical settings lean towards 316. Treat that as a clue and no more, because either grade can turn up almost anywhere.
The only dependable way to separate the grades is to measure the chemistry. A handheld X-ray fluorescence (XRF) analyser reads which elements are in the metal and matches them against a library of alloy grades, which is how molybdenum shows up.
It can’t measure carbon, so it won’t tell 316 from 316L. Chemical spot-test kits that react to molybdenum also exist, but they indicate that it’s present rather than naming the grade. Most households don’t own either, so describing where an item came from and sending photos ahead of time helps a lot.
If you’re not sure, say so. “I think it’s 316, but I can’t confirm it” is far more useful than a confident guess.
No. Both are normally non-magnetic, so a magnet that doesn’t stick tells you the piece is an austenitic stainless, but not which one. The cheaper, low-nickel 200-series is also non-magnetic when annealed, so a magnet can’t confirm 304 or 316.
Both can also pick up a weak pull where the steel has been bent, formed or welded, such as the corners of a sink bowl or the threads on a bolt. A faint tug on a bent edge doesn’t mean it isn’t 304 or 316.
Where a magnet does earn its keep is in spotting magnetic stainless. The 400-series grades, such as 430, are magnetic and contain little or no nickel, so they’re worth less.
If a magnet grabs hard on a flat, unworked area, the piece is probably 400-series stainless (or isn’t stainless at all, such as plated or painted steel), not 304 or 316. Check a few spots, not just an edge. Appliance panels, trim and some cookware are places where this type can turn up.
Commercial kitchens are a big source of 304: benchtops, sinks, splashbacks, shelving, prep tables, pots and utensils, along with brewing and dairy equipment. At home, kitchen sinks and cookware are commonly 304-type, though not every one is.
316 tends to appear where salt, chemicals or strict hygiene matter. Think marine hardware, coastal handrails and balustrades, pool fittings, and tanks or pipework from chemical, pharmaceutical and some food-processing sites.
Renovation scrap often mixes the two. A rail might have 316 posts with 304 infill, or a sink might have a stainless bowl bolted to a steel frame. If you can’t tell what’s what, keep items separated by where they came from rather than tipping everything into one heap.
Scrap is valued by what’s in it. 316 has more nickel than 304 and adds molybdenum on top, so it generally brings in more per kilo. The 200- and 400-series carry less nickel than 304 or 316 and usually sit below both, and plain steel and iron sit well below stainless again.
How a yard handles a mixed lot varies, but sorting before you arrive means each piece can be assessed for what it actually is, rather than lumped in with the rest. At West Coast Metals we sort and weigh each load by metal type instead of paying one rate on bulk weight, so a clear description of your pile still helps speed things up.
Prices also move with the market and with the condition and quantity of what you bring, which is why a published list works as a guide and not a quote. You can see our current guide ranges on our page for scrap metal prices in Perth.
You don’t need to be a metallurgist, but a little preparation makes the assessment quicker and more accurate. Our guide to sorting scrap metal for recycling covers the basics across all metals. For stainless, these are the points that matter most:
West Coast Metals Recycling buys stainless steel scrap from domestic, commercial, industrial and mining customers. You can bring it to our yard at 22 Crocker Drive, Malaga, or ask about collection. For larger volumes, one of our drop-off bins may suit (terms and conditions apply).
Once your metal is sorted and weighed, we pay in cash or by bank transfer. Our page on stainless steel recycling in Perth has more on what we take and how we work.
Not sure of the grade? Send clear photos with a short description of the item, how much there is and its condition to info@westcoastmetals.com.au, and we’ll come back with a free quote. You can also call us on 08 9248 2207 or 0477 331 630.
We’re open Monday to Friday from 8:00 am to 4:00 pm and on Saturday from 8:00 am to 1:00 pm. We’re closed on Sunday.
Generally, yes. 316 contains more nickel than 304 and also has molybdenum. The actual figure depends on the market, the condition of the metal and how much you have.
Check for a stamp or paperwork first, then think about where the item came from. A magnet won’t separate them. Confirming the grade properly takes a chemical analysis, such as a handheld XRF reading.
It depends on the type. Austenitic grades, including 304, 316 and the 200-series, are normally non-magnetic but can show a weak pull where the metal has been bent or welded. The 400-series grades are magnetic.
It stands for low carbon, which helps when the steel is welded. 316L still contains molybdenum, so it belongs in the same family as 316.
No. Sorting helps, but you don’t need to be certain. Bring your stainless grouped by where it came from, tell us what you know, and we’ll sort and weigh it by metal type.