Metals · Fe + Cr + Ni

Stainless steel

Updated October 16, 2026

Stainless steel is iron alloyed with at least 10.5% chromium, which forms an invisible skin of chromium oxide that stops rust and tarnish. Jewellery uses 316L "surgical" steel, which adds nickel and molybdenum for extra corrosion resistance. It is hard, waterproof and cheap: you can shower, swim and sweat in it. It is greyer than silver and very hard to resize.

What it is: Iron, chromium (16 to 18% in 316L), nickel and molybdenum
Tarnish: None: the chromium oxide skin heals itself
Invented: 1913, by Harry Brearley in Sheffield, England
Jewellery grade: 316L, the "L" meaning low carbon

Why it does not rust

Chromium in the steel reacts with oxygen to form a layer of chromium oxide only a few atoms thick. It is invisible, it seals the iron away from water and air, and if it is scratched it re-forms within seconds.

Good enough for a Rolex

Stainless steel is not a cheap compromise. Rolex makes its steel watches from Oystersteel, its own grade of 904L stainless steel, and most luxury sports watches are steel. Jewellery steel is usually 316L, the grade used for surgical instruments and body piercings.

A stand-in for silver

Polished stainless steel looks a lot like silver at a fraction of the price, and unlike silver it never tarnishes. It is a little greyer and heavier, and it cannot be resized, but for a chain you wear in the shower, the sea and the gym it is the better choice.

Sensitive skin

316L contains nickel, but it is locked tightly into the steel and very little comes out, so most people with mild nickel sensitivity wear it without trouble. For a true nickel allergy, titanium or platinum is the safer choice.

Gold-coloured steel

Many cheap "gold" chains are stainless steel with a gold-coloured coating, either thin gold plating or a hard PVD (physical vapour deposition) coating. PVD lasts much longer than ordinary plating; the listing should say which.

The atoms inside

Shares are for 304 (18/8) steel, the usual jewellery and kitchen grade; 316L adds about 2% molybdenum. A simplified picture: real electrons are fuzzy clouds, not dots on rings, but the count in each shell is real. The cube shows how the atoms stack in the solid metal.

IronFeAtomic number26Atomic mass55.845Electrons per shell2 · 8 · 14 · 2CrystalBody-centred cubicAn atom at every corner of a cube and one in its centre. Stiffer and less ductile than face-centred metals.Iron is the most common element in the Earth by mass, most of it in the core.

ChromiumCrAtomic number24Atomic mass51.996Electrons per shell2 · 8 · 13 · 1CrystalBody-centred cubicAn atom at every corner of a cube and one in its centre. Stiffer and less ductile than face-centred metals.Chromium is what makes stainless steel stainless: at 10.5% or more it forms an invisible oxide skin that heals itself when scratched.

NickelNiAtomic number28Atomic mass58.693Electrons per shell2 · 8 · 16 · 2CrystalFace-centred cubicAn atom at every corner of a cube and one in the middle of every face: the tightest way to stack spheres. Metals stacked this way bend and stretch easily, which is why they can be drawn into fine wire.Nickel keeps the iron atoms in 304 stainless steel stacked face-centred, which makes it tough and non-magnetic. It is also the most common metal allergy.

Electron shells from each element's ground-state configuration; crystal structures at room temperature. Source: electron configurations of the elements and crystal structures of the elements.

Titanium vs stainless steel

	Titanium	Stainless steel (316L)
Weight	About 4.5 g/cm³: very light	About 8 g/cm³: nearly twice as heavy
Colour	Darker, warmer grey	Brighter, closer to silver
Scratches	Pure titanium scratches more easily	Harder wearing, keeps a polish longer
Sensitive skin	Implant grade (F136) has no nickel: the safest choice	Contains nickel locked into the alloy; fine for most people
Price	More: chains often $50 to $100	Less: chains often $10 to $30
Rust and tarnish	Never	Never
Resizing	Hard	Hard
Best for	Allergies, new piercings, all-day comfort	Value, shine, chains you swim and shower in

Real stainless steel pieces on Amazon

Each listing's own metal details were read on October 16, 2026 and match the title; we show its star rating, and leave out anything under 4 stars. Prices change, so the link goes to the live listing.