“Food grade” is the most overworked sticker in a stainless catalogue. The old Melbourne shop sold 304 for benches and food handling, which is the correct instinct. It did not invent a fourth alloy called food grade. Neither should you.
In Australia, food contact is a regulatory and hygiene problem, not a marketing adjective. FSANZ sets the Food Standards Code. State health departments and local councils enforce kitchens. None of them publish a magical stainless grade that replaces cleaning, coving and a drain that works. ASSDA’s food and beverage notes treat stainless as a cleanable, corrosion-resistant surface — not as a certificate you bolt on after a poor weld.
This journal is independent editorial. It will not sell you a bench and it will not invent a council checklist. Your certifier and the Food Standards Code still win. The grades and alloys hub sits behind the chemistry.
What the metal has to do
A food surface has to be cleanable, non-toxic in ordinary use, and resistant enough that it does not pit into a bacterial hotel. Austenitic 304 has been that metal for a century of dairies and canteens. Atlas Steels grade data still lists 304 / 304L as the workhorse austenitic; 316 as the molybdenum upgrade when chlorides or harsh chemicals are part of the wash. Ferritic 430 appears in some appliances; it is not your first choice for a welded wet bench — see what 430 stainless steel is for.
Finish matters as much as alloy. A No. 4 brushed face is the Australian kitchen default because it hides light scratching and still wipes. A wild grit pattern or an unsealed weld is a hygiene defect. Read stainless steel finishes. 2B mill finish can be honest on unseen plant; a dairy table wants a specified polish and a continuous weld.
Chemistry, not a sticker
304 (UNS S30400) is chromium-nickel austenitic. 304L is the weldable low-carbon cousin. 316 / 316L adds molybdenum for chlorides. None of these numbers say “food.” Food is the duty: contact, splash, washdown, temperature, and the chemicals in the bucket.
| Alloy | Food-side honesty in Australia | Leave it |
|---|---|---|
| 304 / 304L No. 4 | Café benches, indoor canteens, most splashbacks | Brine rooms, coastal open kitchens, heavy chlorine |
| 316 / 316L | Seafood, pickle, chlorinated plant, salt air kitchens | When 304 already meets the duty and the budget is the brief |
| 430 | Some appliance skins and bowls designed around it | Welded wet benches, outdoor food, anything sold as 304 |
| “Food grade” with no number | A story | The purchase order |
How to identify a grade still applies in a kitchen. A magnet on a “food-grade bench” may be 430. A non-magnetic bench is not automatically 316.
Australian duty: café, plant, coast
Indoor café and canteen
304 No. 4 is the default. That is what the historic custom-cut counter expected for food handling sheet. Thickness is a fabrication and denting decision, not a hygiene grade. Returns, upstands and a fall to the waste do more for an inspector than an extra point of nickel.
Food plant
Dairies, meat rooms and beverage plant add weld quality, drainability and a cleaning chemical that may be nastier than a café detergent. Engineers name 304L or 316L, a surface finish, and a procedure. Welding 304 and 316 and passivation after fabrication are part of the hygienic story. Sugared purge inside a tube is a defect, not a patina.
Coastal and outdoor food
An open kitchen on the Australian coast is a chloride job that happens to serve food. Read 304 versus 316 and marine-grade language. Salt air plus a bleach wipe is two attacks. 316L, washable finish, A4 fasteners, and a care note beat a “food-grade marine” sticker.
Detailing that inspectors actually see
Coving, corner guards, and the absence of a dirt step at the wall are the old catalogue’s food-side wisdom. Horizontal ledges, raw screw threads in a splash zone, and silicone used as a structural fillet are how a new bench fails its first audit.
Welding should be continuous where the surface is meant to be washed. Heat tint should come off. Passivation is not optional theatre on a dairy table. Cleaning without chloride damage belongs in the operations manual, because bleach is still how a 304 bench gets the brown freckles people blame on “cheap imported steel.” Tea staining in a kitchen is often chemistry in the bucket, not a wrong mill.
Fasteners above food should not be the first rust. Carbon screws through a 304 top are a stain and a hygiene complaint. Match the alloy. Isolate mixed metals.
When 316 is the food-grade choice
- Brine, pickle, and seafood rooms.
- Coastal open kitchens that eat salt and smoke.
- Wash regimes that lean on chlorine or strong sanitisers.
- Anything already specified 316 by a plant engineer.
Otherwise 304 is not a downgrade. It is the metal Australian benchtops are made of. Paying for 316 to impress a landlord is how cafés blow a fit-out budget. Paying for 304 in a brine tank is how plant owners buy pits.
Duplex appears in some chloride-heavy process — see duplex versus 316 — but not as a café upgrade. Do not let a merchant escalate a sandwich bench into plant plate.
Failure modes
Adjective without a number. “Food grade 1.2 mm” on a docket. Could be 430. Could be 304 uncertified. Could be coated steel in a photograph.
Bleach pits on honest 304. The alloy was right. The sanitiser was a chloride attack. Train the cleaner; do not replace the bench with 316 as the first move unless the duty truly needs it.
Unsealed welds and pinholes. A bacterial hotel with a mill certificate. Finish the weld.
430 sold as a food bench. Magnet sticks, paper missing, wet use. Identify, then decide whether the part was ever designed for that duty.
Coastal café in 304. Open to salt, proud of the food-grade sticker. The marine and outdoor essays apply even when the product is a pass.
Swarf in the polish. A site cut with a carbon blade, then a health inspection photograph of rust specks. That is contamination, not the wrong grade — until you also failed to name the grade.
Specification language and how to order
Write 304 or 316L, the finish, the thickness, and “food contact, hygienic welds, coved upstands” on the order. Keep the mill certificate. If a supplier can only say food grade, ask them which UNS number that is.
A usable sentence: “304 No. 4, 1.2 mm, food-contact benchtop, continuous welds, coved rear upstand, passivate after fabrication, mill certificate to be supplied.” Change 304 to 316L when brine, chlorine or coastal air is in the brief. Add A4 if the assembly is fastened in a wet or outdoor zone.
Do not write marine grade on a kitchen order unless you also write 316 and mean salt. Do not write food grade on a coastal rail and think you have specified a barrier — that job is 316 balustrades.
Certificates, not adjectives
Plant owners and importers may need evidence the material is suitable for contact. A mill certificate naming 304 or 316 is the start. A verbal “it’s food grade” is not. Trace the heat if the plant’s quality system asks. Identify at purchase, not at the opening audit.
Coastal care still belongs in an open kitchen handover: wash the salt, drain the ledges, keep bleach off the metal unless the chemical regime was designed for it.