"Stainless steel" is not one material — it is a family of alloys, and the differences show up fast in a wet, salty, acidic kitchen. The two grades you will meet most often are 304 and 430, with 316 reserved for the harshest jobs. The practical questions people search are almost always the same: is it food-safe, will it rust, is it magnetic, and how thick is it. This guide answers those without the metallurgy lecture.
The headline difference is nickel. 304 contains roughly 18% chromium and 8% nickel (you will see it called "18/8"), which is what gives it strong corrosion resistance against moisture and food acids. 430 has similar chromium but little or no nickel, so it costs less and resists corrosion adequately in dry, low-exposure spots — but it can spot and rust where 304 shrugs it off. 316 adds molybdenum for extra resistance to salt and chlorides.
| Grade | Nickel | Magnetic? | Corrosion resistance | Typical use |
|---|---|---|---|---|
| 304 (18/8) | ~8% | No (non-magnetic) | High | Prep tables, sinks, food-contact surfaces |
| 430 | ~0% | Yes (magnetic) | Moderate | Exterior panels, splashes, low-exposure trim |
| 316 | ~10% | No | Highest | Coastal, heavy-brine, cleaning-chemical exposure |
A handy shop-floor test: a magnet sticks firmly to 430 but not to 304 or 316. It is a rough check, not proof of grade, but it separates the ferritic 430 from the austenitic grades quickly.
People search "is 304 food grade" constantly. The honest answer: both 304 and 430 can meet sanitation standards when they are properly finished, welded, and easy to clean — the surface finish and weld quality often matter as much as the alloy number. That is exactly what third-party sanitation certification checks. If a piece touches food or is hard to reach for cleaning, 304 is the safer default because it holds up to acidic foods and repeated washdowns. See what NSF-certified equipment means for how certification ties to material and construction.
Gauge measures thickness, and the scale runs backwards — a lower number is thicker. For work surfaces, 14 and 16 gauge are heavy-duty and resist denting under real abuse; 18 gauge is a common mid-weight for tables and shelving; 20–22 gauge is light and better suited to panels than to work you will pound on. Thicker steel costs more and weighs more, but it stays flat and survives years of carts, pans, and cleavers.
| Gauge | Relative thickness | Good for |
|---|---|---|
| 14 | Thickest common | Heavy prep tables, dish tables |
| 16 | Heavy | Work tables, sinks under hard use |
| 18 | Medium | General tables, shelving |
| 20–22 | Light | Panels, enclosures, trim |
Stainless resists corrosion because of an invisible chromium-oxide layer; the goal of good cleaning is to protect that layer. A few honest rules: wipe with the grain, use warm water with a mild detergent or a dedicated stainless cleaner, and rinse and dry to avoid water spots. Avoid steel wool and chloride-heavy or abrasive cleaners — they scratch the surface and can trigger the very rust people blame on "bad steel." If rust spots appear, they are often surface contamination from carbon-steel tools, not failure of the stainless itself.
Rule of thumb: spend on 304 and adequate gauge where food and hands touch; save with 430 on outside panels no one scrubs. This is educational information, not a purchasing or compliance ruling — verify grade requirements with your local health authority.