Stainless Grade Selection 2026: 201 vs 304 vs 316, What Each Costs, and Why "304/201" on a Spec Sheet Is the Real Problem

Three grades cover almost all stainless door hardware. They are indistinguishable to a buyer holding two samples, and the difference between them shows up eighteen months later on a building nobody can easily revisit.

That gap — identical on the desk, different on the wall — is why this is worth being precise about, and why a supplier's vagueness here costs more than vagueness anywhere else in a catalogue.

What actually separates them

All three are austenitic stainless steels. The differences are in what does the work of resisting corrosion, and what was substituted to make the alloy cheaper.

The single sentence that carries most of the practical difference: **molybdenum is what resists chloride.** That is why 316 is the coastal and pool grade and 304 is not, and it is not a marketing distinction — it is a specific chemical mechanism against a specific attack.

201's story is different. Nickel is the expensive element, and 201 substitutes manganese and nitrogen for part of it. The result performs acceptably in dry interior use and degrades noticeably faster wherever chloride, humidity or pollution is present.

Where each one belongs

**201** — interior doors in dry, conditioned buildings; back-of-house; furniture and cabinet hardware; anywhere the cost difference matters and the environment is benign. It is not a fraud grade; it is a legitimate material used outside its range far too often.

**304** — the default for architectural hardware. Entrances, external doors inland, most commercial specification. If a specification says "stainless" and means one thing, it means this.

**316** — coastal sites, swimming pools and their plant rooms, industrial atmospheres, anywhere de-icing salt is used, and any external opening the owner will not clean. Our corrosion page covers why a sheltered coastal position can be worse than an exposed one.

The cost question, answered honestly

The price ladder follows nickel and molybdenum, and the gaps are not symmetrical. 201 to 304 is a real saving; 304 to 316 is a smaller premium than most people expect once the part is finished and packed, because on small hardware the raw material is a minority of the delivered cost.

That asymmetry is worth knowing because it changes the decision. Choosing 201 over 304 to save money is a genuine trade with a genuine risk. Choosing 304 over 316 on a coastal project to save money is usually trading a large future cost for a small present one — the metal is a fraction of the price of a lever that has been machined, polished, plated, packed and shipped.

Nobody should take a precise percentage from a web page, ours included, because it moves with the nickel market. Ask for the difference on your actual order; it is a real number your supplier can produce that week.

Why "304/201" on a specification is the real problem

Here is the part of this page that matters most, and it is about how grades are written rather than about metallurgy.

A specification line reading "Stainless Steel 304/201" does not mean an alloy. It means **the factory will supply one of those two**, and the buyer will not be told which, and cannot tell by looking.

For an interior office door that may be entirely acceptable. For an external door on a coastal site it is the whole risk, written in a form that looks like a specification. The two grades are visually identical; the difference appears as pitting after the first winter.

So when you see a pair of grades separated by a slash, treat it as an unanswered question rather than as a specification. The useful reply is one line: "which grade will be supplied on this order, and can that be stated on the invoice?"

The grade is not the finish, and the finish does not rescue the grade

A recurring assumption worth dismantling: that a good finish compensates for a lower grade. It does not, and understanding why makes several other decisions easier.

Stainless resists corrosion because chromium forms a thin passive oxide layer that re-forms whenever it is damaged, provided oxygen can reach the surface. That is a property of the metal, continuous through the whole section, not a coating.

A satin, mirror or brushed finish changes the surface texture and therefore how easily deposits cling to it — a mirror finish sheds dirt better than a coarse brushed one, which is a real and useful difference. What it does not do is add corrosion resistance the alloy does not have. Polished 201 is 201.

A PVD or plated coating over stainless is a different matter again: it is a coating, it has its own wear and adhesion behaviour, and where it is worn through or cut through the metal underneath is doing the work. If that metal is 201 on a coastal door, the coating has delayed the problem rather than solved it.

So specify the grade for the environment and the finish for the appearance and the cleaning regime. They are two decisions and neither substitutes for the other.

The four things that actually damage stainless on a building

**Chloride.** Covered above and the main event. It attacks the passive layer locally and produces pitting, which is small, deep and much harder to see early than general rust.

**Iron contamination.** Free iron transferred onto a stainless surface rusts, and the rust looks exactly like the stainless failing. It arrives from grinding sparks during construction, from steel wool used to clean, from carbon steel fixings, and from tools. The stainless underneath is usually fine; the remedy is cleaning and passivation, not replacement. This is the single most common false alarm in the first year of a building.

**Tea staining.** A brown surface discolouration common on coastal stainless, usually cosmetic rather than structural. It is strongly associated with surface roughness and with lack of rinsing, which is why it appears first on sheltered surfaces that rain never washes.

**Mechanical damage.** Scratches and dents break the passive layer, and it re-forms — but a scratch that traps dirt or chloride re-forms more slowly, and deep scratches in a coastal environment become pit initiation sites.

Three of those four are about what happens after installation, which is why our corrosion page argues that a maintenance plan is part of a material specification rather than an afterthought to it.

The magnet test, and why it proves less than people think

The common site test is to hold a magnet against the part: if it sticks, the theory goes, it is 201; if it does not, it is 304.

Treat that as a hint and never as a result. Annealed 304 is essentially non-magnetic, but cold working — drawing, stamping, forming a lever — makes it measurably magnetic, and plenty of genuine 304 hardware responds to a magnet at a formed edge. 201 is frequently weakly magnetic, so the test produces false positives in both directions on exactly the parts hardware is made from.

It also cannot distinguish 304 from 316 at all, and that is usually the more expensive question.

If the grade genuinely matters, the answer is documentary or analytical: a material certificate from the mill, or a portable analyser on the part. Our material traceability page covers what a certificate has to contain to be evidence rather than a letter.

What our own catalogue says, counted

We should apply that standard to ourselves before asking anyone else to. Counted from the material rows of every product in our catalogue that mentions stainless steel.

**Seventy-two per cent of our stainless products do not name a grade at all**, and a further 73 name two. Sixteen out of 313 answer the question this page says a buyer must ask.

That is not a good number and printing it is deliberate. A buyer who reads it knows exactly what to do — ask for the grade, in writing, per order — and a buyer who assumed the catalogue answered it would not have asked.

The reason it is that way is mundane rather than sinister: the grade is a purchasing fact that lives in the factory's material records, and the catalogue was built from product descriptions rather than from those records. It is being closed by reconciliation, model by model, not by writing a plausible grade into 224 rows.

What to put on your order

Name the grade, not the family. "304" rather than "stainless".

Say the environment if it is not ordinary interior — coastal, pool, industrial, coastal-and-sheltered — because that lets a supplier tell you when your grade is wrong rather than quoting it.

Ask for the grade on the invoice or packing list. That turns it from a conversation into a document, and our material traceability page explains what a stronger document would be if the project needs one.

And specify the fixings to the same grade. A 316 lever held by 201 screws corrodes at the screws, which is the part everybody looks at.