304 Stainless vs 316 Stainless
304 and 316 are the two workhorse austenitic stainless steels, and the choice almost always comes down to one question: how aggressive is the corrosion environment? Mechanically and in fabrication they behave nearly identically, so the decision is driven by chemistry and cost, not strength.
The verdict
Choose 304 for the vast majority of indoor, structural, food, and architectural work — it is cheaper, widely stocked, and corrosion-resistant enough for most uses. Choose 316 when chlorides are present: marine, coastal, de-iced, or chemical/pharma environments where its added molybdenum resists pitting and crevice corrosion. If salt or acids touch the part, pay for 316; otherwise 304 wins on cost.
Side-by-side data
| Property | 304 Stainless | 316 Stainless |
|---|---|---|
| Category | Stainless Steel | Stainless Steel |
| Density (g/cm³) | 8.0 | 8.0 |
| Tensile strength (MPa) | 515 | 515 |
| Yield strength (MPa) | 215 | 240 |
| Elongation (%) | 40 | 40 |
| Hardness | 201 HB | 217 HB |
| Max service temp (°C) | 870 | 870 |
| Machinability | ●●●●● | ●●●●● |
| Corrosion resistance | ●●●●● | ●●●●● |
| Relative cost | ●●●●● | ●●●●● |
| Thermal cond. (W/m·K) | 16 | 16 |
| Typically used for | General corrosion-resistant parts | Marine, medical & chemical environments |
Which should you choose?
Choose 304 Stainless if…
- The part lives indoors or in a dry, non-chloride environment (kitchen equipment, railings, enclosures, structural brackets).
- Cost and availability matter — 304 is the default stock grade and noticeably cheaper than 316.
- You need food-contact or sanitary surfaces without salt/brine exposure (sinks, tanks, cookware, beverage equipment).
- You want the easiest sourcing in sheet, bar, tube, and fasteners with the broadest supplier base.
- The application is general architectural or decorative work away from coastal salt air.
Choose 316 Stainless if…
- The part sees chlorides — seawater, coastal/salt-spray air, road de-icing salt, or pool chemistry.
- It contacts acids, brines, or aggressive process chemistry (pharma, chemical processing, food brining/pickling).
- Pitting and crevice corrosion are failure modes you cannot tolerate (fasteners, welds, tight gaps in marine hardware).
- It is a medical or surgical implant/instrument where 316/316L biocompatibility is specified.
- Long service life with minimal maintenance in a harsh environment justifies the higher material cost.
Key differences that matter
- Corrosion is the real differentiator: 316 adds ~2-3% molybdenum, which dramatically improves resistance to chloride pitting and crevice attack that 304 cannot withstand.
- Strength is essentially a tie — both are austenitic with similar yield, tensile, and ductility, so 316 is not chosen for being 'stronger.'
- Cost is the trade-off going the other way: 316 typically runs 20-40% more than 304, driven largely by molybdenum and nickel content.
- Both machine and weld similarly — gummy, work-hardening, low thermal conductivity; specify the low-carbon L grades (304L/316L) for welded parts to avoid sensitization.
- Neither can be hardened by heat treatment; both are non-magnetic when annealed and offer comparable high-temperature oxidation resistance, with 316 slightly better in some hot-corrosive service.
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Open the Material SelectorGet a Quote →Frequently asked questions
Is 304 stronger than 316?
No — they are effectively equal. Both are austenitic stainless steels with very similar yield strength, tensile strength, and ductility. 316 is chosen for corrosion resistance, not mechanical strength, so don't upgrade to 316 expecting a stronger part.
Which is cheaper, 304 or 316?
304 is cheaper, usually by about 20-40%, because 316 contains added molybdenum and more nickel. 304 is also the more commonly stocked grade, so lead times and availability tend to favor it as well.
Can 304 be used near saltwater or the coast?
Not ideally. In chloride-rich environments (marine, coastal salt air, de-icing salt) 304 is prone to pitting and crevice corrosion and will stain or fail over time. 316's molybdenum makes it the correct choice for salt exposure.
Are 304 and 316 equally machinable and weldable?
Yes, very nearly. Both are gummy, work-harden quickly, and have low thermal conductivity, so use sharp tools, firm feeds, and flood coolant. For welded assemblies, specify low-carbon 304L or 316L to prevent carbide sensitization and intergranular corrosion.
Are both grades magnetic?
In the annealed condition both are essentially non-magnetic. However, cold working — bending, forming, or machining — can induce slight magnetism in 304, and to a lesser degree 316, so a weak magnetic response does not reliably distinguish grade or quality.
Property values are typical/nominal figures for early-stage guidance only and vary by temper, grade, supplier and heat treatment. Confirm critical specifications against a certified datasheet or with an mfgiq engineer before production.