18/8 and 18/10 are the same AISI 304 alloy family: both contain roughly 18% chromium, with 8% nickel in 18/8 and 10% nickel in 18/10, the only practical difference being that 2-point nickel bump [S3][S4].
Chromium is the element that forms the passive oxide layer giving 304 its "stainless" behavior, while nickel stabilises the austenitic structure, deepens corrosion resistance in chloride-bearing and acidic food service, and boosts ductility, polish, and formability for deep-draw cookware [S3][S5].
Composition and What the Numbers Actually Mean
The cutlery-style labeling system reports the weight-percent of chromium (first figure) and nickel (second figure) in the alloy; 18/0 therefore contains 18% chromium and essentially no nickel, 18/8 contains 8% nickel, and 18/10 contains 10% nickel [S3][S4]. The British Stainless Steel Association confirms that 18/8 maps directly to AISI 304 in the American Iron and Steel Institute system, and 18/10 sits at the top of the same 304 nickel range rather than being a distinct grade [S4]. Cupindy's engineering-grade writeup makes the same point: "18/10 and 18/8 are not different grades from 304, they are 304," with 18/10 simply having nickel near the upper end of the 304 window [S5].
Beyond chromium and nickel, both grades carry the residual carbon, manganese, silicon, and iron typical of 304, and they share the same austenitic, non-magnetic microstructure in the annealed condition. Misumi's industrial summary notes that 18/0 is the variant that breaks this pattern, since 0% nickel pushes the alloy into the ferritic 430 family and makes it magnetic, which is exactly why automated handling lines and induction-base cladding prefer it [S3].
Corrosion, Mechanical, and Forming Behaviour
Nickel is doing real work in 18/10: Caraway's 2025-05-15 guide flags the austenitic structure as the reason the higher-nickel grade keeps a polished finish through dishwasher cycles and resists pitting from acidic foods better than 18/8 [S2]. The same source notes that 304 (18/8 or 18/10) can be processed through cold rolling, deep drawing, or welding into sheet, bar, pipe, and custom components, and is specified where moisture, heat, and cleaning chemicals hit the part in service [S3].
Mechanical behaviour is close enough between 18/8 and 18/10 that the specifier usually selects on corrosion and finish rather than strength: both deliver the familiar 304 tensile strength in the 515–620 MPa range, elongation above 40%, and a maximum service temperature near 870°C in intermittent exposure (continuous service capped lower). Where the 2-point nickel delta matters is chloride pitting, acidic food contact, and mirror-polish retention, all of which lean in 18/10's favour [S3][S5]. For non-food industrial buyers, the practical upshot is that 18/8 is "plenty tough for everyday kitchen use" and most chemical-handling hardware, while 18/10 is the over-spec choice when finish, deep draw, or long-term acid exposure are on the data sheet [S2].
Selection Criteria: 18/10 vs 18/8 vs 18/0
Cupindy's cookware table gives the clearest buyer-facing rule: 18/10 (304) is the default pick for everyday cookware, 316 (marine grade, with 2–3% molybdenum) is the premium upgrade for salty or acidic cooking, and 18/0 (430) is the magnetic budget option for induction plates and appliance panels [S5]. Translating that to industrial procurement: if the part sees chloride, fruit acid, or aggressive wash-down, push the nickel to 10% (18/10) or step up to 316; if the part is structural, indoor, or coated, 18/8 saves cost without measurable life penalty; if the part must be magnetic for induction heating or sorting, drop to 18/0 and accept the lower corrosion margin [S3][S5].
Cost moves in the same direction: 18/0 is the cheapest of the three because it skips nickel entirely, 18/8 sits in the middle, and 18/10 commands the highest unit price for a 2-point nickel lift, justified mainly by finish and pitting margin rather than strength [S3]. For deeper material context on how 304 fits into the broader stainless family used in piping and process equipment, the stainless steel reference page lays out the full grade taxonomy, while stainless pipe covers the welded and seamless tube variants commonly ordered in 304 for food, dairy, and chemical service.
Process and Manufacturing Route
All three grades follow the same primary melt path: raw iron ore, chromium, nickel, and carbon are charged into an electric arc furnace, refined via argon oxygen decarburization (AOD) to bring carbon down and chromium up to spec, then cast into slabs, blooms, or billets [S2][S3]. After casting, the semi-finished shapes are hot-rolled, annealed at roughly 1,040°C to soften the austenite and recrystallise the grain, and pickled in an acid bath to remove mill scale and restore the passive chromium oxide layer [S2][S3].
Downstream forming diverges by application: flatware and cookware bodies go through cold rolling and deep drawing, cutlery blanks are stamped and tumble-polished, and industrial bar or pipe stock is machined, welded, or cold-drawn to finished tolerances [S2]. The shared process is one of the reasons 18/8 and 18/10 are routinely substituted for each other in buyer specs, the equipment, the annealing cycle, and the pickling chemistry are identical, only the nickel addition at the AOD stage changes [S3].
Standards, Magnetic Behaviour, and Common Pitfalls
Work-hardening is the one trap that catches specifiers cold-rolling 304 sheet: heavy cold reduction can transform a portion of the austenite to martensite, making 18/8 or 18/10 slightly magnetic at the surface even though the annealed alloy is non-magnetic [S3]. 18/0 (430) does not have this ambiguity, it is ferromagnetic in all conditions, which is why conveyor lines, magnetic sorting, and induction-clad cookware base layers lean on it [S3][S5].
For spec-driven buyers working on cookware, cutlery, or hygienic process lines, a closer read on how these austenitic grades compare with martensitic and precipitation-hardening stainless for forged parts is in the 15-5 PH vs 17-4 PH selection guide, useful when the part also needs higher strength than 304 can deliver. Likewise, when 304 is being marked or engraved rather than formed, the MOPA vs Q-switched fiber laser comparison covers the surface-treatment trade-offs that come up with austenitic stainless.
Who 18/10 Is For, and Who Should Walk Past It
Spec 18/10 when the part is polished mirror-finish flatware, premium cookware, pharmaceutical or high-purity food-contact surfaces, deep-drawn kitchen sinks, or any 304 component where the buyer wants the highest pitting and acid margin available without leaving the 304 family [S3][S5]. Spec 18/8 when the application is general industrial fabrication, food processing skids, brewery and dairy tubing, kitchen utensils, or any part where the extra 2% nickel does not justify the price premium, the corrosion delta is measurable in the lab but rarely material in indoor service [S2][S3]. Walk past both toward 18/0 (430) when magnetic response is required for induction heating, automated sorting, or low-cost stamped trays, accepting the lower corrosion margin as the cost of going nickel-free [S3][S5].
For heavier-gauge stainless work like structural angles, pressure pipe, or process vessels, the alloy steel and carbon steel reference pages help frame where 304 sits against low-alloy and carbon alternatives when corrosion is not the binding constraint.
Next signals worth tracking: nickel spot price as the 18/10 vs 18/8 cost gap driver, 316Ti and 444 ferritic launches in the cookware category, and any update to ASTM A240 / EN 10088-2 chemical-range tables that shifts the 304 nickel window and re-defines where 18/10 starts and ends.