Buying Guides
Stainless Steel Kitchen Sinks: The 4 Specs That Matter
By the Hill & May team
Updated 2026
Stainless steel kitchen sinks are the default choice in British kitchens for good reason: nothing else takes a hot roasting tin, a dropped casserole and forty years of scouring quite as well. The problem is that a budget sink and a premium one look almost identical in a showroom photograph, and the words on the label are chosen to blur the difference. Four specifications separate them, and once you know what to look for you can judge any sink from its spec sheet in about thirty seconds. Everything else is styling.
This guide covers those four, then the sizing and mounting decisions that determine whether the sink you like actually fits the kitchen you have.
Spec 1: the steel grade
You want grade 304, sometimes written 18/10 or 18-10. Those numbers are the alloy: 18% chromium, 10% nickel. Chromium forms the passive layer that makes the steel stainless; nickel is what gives it the corrosion resistance and the slightly warmer tone. You will also see 18/8, which is the same 304 family with slightly less nickel and is perfectly acceptable.
What you do not want is grade 201. It substitutes manganese for much of the nickel, costs the manufacturer noticeably less, and is meaningfully more prone to staining and pitting in a wet, salty environment. Sinks in 201 rarely announce it. If a listing does not state the grade at all, at the budget end, assume the worst and look at the next one.
Grade 316 adds molybdenum and appears occasionally at the premium end. In a domestic kitchen it is more than you need; it belongs in coastal and marine settings.
Spec 2: thickness, in millimetres not gauge
American listings talk in gauge, where lower means thicker. British ones usually give millimetres, which is more useful. The practical ladder:
- 0.6mm: budget pressed sinks. Flexes under a full washing-up bowl, drums loudly, dents if you drop something heavy. Fine for a utility room or a rental.
- 0.8mm: the mainstream mid-market. A reasonable compromise and what most branded inset sinks use.
- 1.0mm to 1.2mm: premium pressed and most handmade sinks. Feels solid under the hand, resists denting, and is quiet enough that the sound deadening actually has something to work with.
Thickness matters less than people assume for durability, since a 0.8mm 304 sink will outlast most kitchens. It matters a great deal for how the sink feels, and feel is what you notice every day.
Spec 3: corner radius, and the handmade question
Pressed (or “drawn”) sinks are stamped from a single sheet, so the bowl corners have a generous curve, often R25 or larger. Handmade sinks are cut and welded from flat sheet, which allows much tighter corners.
The industry shorthand is the radius in millimetres. R10 has become the sweet spot: square enough to read as a modern handmade sink, curved enough that a cloth reaches into the corner. True 90-degree corners look superb and are a nuisance to keep clean, because food dries in the angle and you end up going at it with a brush.
Handmade sinks are usually thicker steel and always more expensive. They are worth it if you are undermounting into stone and want the crisp lines to be the feature. For an inset sink in a laminate worktop, a good pressed sink at 0.8mm or 1.0mm is the sensible buy.
Spec 4: sound deadening
An undeadened stainless bowl is a drum. Two things fix it, and good sinks have both:
Pads. Thick rubberised mats bonded to the underside and sides of the bowl, adding mass so the panel cannot resonate. Look for coverage across most of the bowl exterior, not two postage stamps.
Undercoating. A sprayed layer over the whole underside. It damps what the pads miss and, more usefully in a British kitchen, insulates against condensation forming on cold steel under the cupboard.
If a product photograph shows bare shiny metal underneath the bowl, the sink will be noisy and it will sweat. This is the single most common complaint about cheap stainless sinks, and it is entirely predictable from the listing photos.
Finishes: brushed beats polished
Every stainless sink accumulates fine scratches. The only question is whether you can see them.
Brushed or satin finishes have a directional grain that hides scratching, which is why nearly all serious kitchen sinks use it. Polished or mirror finishes look spectacular for about a fortnight. Linen or textured finishes take the idea further with a fine cross-hatch that disguises both scratches and water marks, and are worth seeking out if you have hard water. PVD coated sinks in gunmetal, brass or black are a physical vapour deposition layer over 304, and the coating is genuinely hard, but any abrasive cleaner will eventually cut through it. We cover that risk in the black kitchen sink guide.
Mounting: inset, undermount or flushmount
Inset (or top-mount) drops in from above and sits on a rim over the worktop cut-out. It is the cheapest to fit, works with any worktop material including laminate, and the rim is the only thing to clean around. This is the right answer for most kitchens.
Undermount fixes beneath the worktop, so you can sweep crumbs straight into the bowl. It needs a solid, waterproof worktop with a properly finished cut-out edge, meaning stone, solid surface or a laminate specifically rated for undermounting. In a standard laminate top, water will find the chipboard core.
Flushmount sets the sink rim level with the surface in a rebated cut-out. It is the most exacting installation and the most expensive, and it looks superb in stone.
If you are weighing stainless against other materials rather than choosing between stainless sinks, our kitchen sink types comparison covers composite, ceramic and copper alongside it, and the Belfast sink guide handles the traditional route.
Sizing it to your cabinet
The number in a listing is the minimum base unit width, not the sink width, and it exists because the bowl, the overflow, the waste and the tap tails all have to fit inside the carcass. A sink for a 600mm cabinet is typically somewhere around 500mm to 550mm wide overall.
Rough guide for standard British units:
- 500mm unit: a compact single bowl, or a small bowl with a short drainer.
- 600mm unit: the most common. A standard single bowl, or a 1.5 bowl.
- 800mm unit: a large single bowl with drainer, or a proper double bowl.
- 1000mm unit: double bowl with drainer, or an oversized single.
Bowl depth is usually 180mm to 200mm, which takes a roasting tin flat. Deeper is not automatically better: a 220mm bowl in a standard 900mm worktop height means more bending, and it eats the space where the waste trap and any water filter need to live.
Two things to check before ordering. First, the number of tap holes: zero, one or two, and it must match the tap you have chosen, because drilling stainless neatly after the fact is not a job to attempt casually. Second, the drainer side, which on reversible sinks is switchable and on many is not. Measure the actual cabinet, not the plan, and check what is already inside it. Our kitchen base units guide covers what the sink cabinet has to accommodate.
Looking after it
Stainless steel is not stain proof; it is stain resistant, and the resistance comes from an invisible chromium oxide layer that repairs itself in air. Two things attack it.
Chlorides. Household bleach and salt both cause pitting, which is permanent. Never leave neat bleach standing in the bowl overnight, which is exactly what many people do to “clean” it. The British Stainless Steel Association’s cleaning guidance is blunt that chloride bleaches and hydrochloric acid pit stainless steel, and recommends soap or mild detergent with a clear water rinse for domestic equipment.
Loose iron. A steel wool pad or a wire brush leaves iron particles embedded in the surface. Those rust, and it reads as the sink rusting when it is really the contamination doing it. Use a nylon pad, and never leave a cast iron pan sitting wet in the bowl.
For everyday marks: warm water and washing-up liquid, dried with a cloth along the grain. Limescale in a hard water area responds to a diluted white vinegar soak followed by a thorough rinse. Tannin marks from tea respond to a hot sodium carbonate solution rather than scrubbing.
What to check before you order
- Grade stated as 304, 18/10 or 18/8. No grade stated at a low price is a red flag.
- Thickness stated in millimetres, 0.8mm or better for a main sink.
- Sound deadening pads plus undercoating, visible in the underside photo.
- Brushed, satin or textured finish rather than mirror polish.
- Minimum cabinet width against your actual unit, measured inside.
- Tap hole count matched to your tap, and drainer side confirmed.
- Waste and overflow: check whether they are included, because on many sinks they are not.
- The warranty, and whether it is genuinely lifetime on the bowl.
Franke’s own guidance on choosing a sink makes the same point about measuring the cabinet width first, and it is the step people skip.
Frequently asked questions
What grade of stainless steel is best for a kitchen sink? Grade 304, also sold as 18/10 or 18/8, is the standard for quality kitchen sinks and is what you should insist on. Grade 201 substitutes manganese for nickel to cut cost and stains and pits more readily. Grade 316 is better still but unnecessary away from coastal conditions.
How thick should a stainless steel sink be? 0.8mm is the sensible minimum for a main kitchen sink, and 1.0mm to 1.2mm is what premium pressed and handmade sinks use. At 0.6mm the bowl flexes and drums. Thickness affects feel and noise more than lifespan, since even a thin 304 sink resists corrosion well.
Are handmade stainless steel sinks worth the extra? They are if you are undermounting into stone and want tight R10 corners as a design feature, and they are usually thicker steel into the bargain. For an inset sink in laminate, a good pressed sink at 0.8mm or 1.0mm gives you most of the benefit for much less money.
Why is my stainless steel sink rusting? Almost always contamination rather than the sink itself. A steel wool pad, a wire brush or a wet cast iron pan leaves iron particles on the surface, and those rust. Remove them with a nylon pad and a mild cleaner. Genuine pitting, small dark permanent craters, usually means bleach or salt was left standing.
Can I put bleach in a stainless steel sink? Not standing, and not neat. Chlorides pit stainless steel permanently, and the damage cannot be polished out. If you use a bleach-based cleaner, dilute it, keep the contact time short and rinse thoroughly with clean water afterwards.
What size sink fits a 600mm cabinet? Usually a sink around 500mm to 550mm wide, either a single bowl or a 1.5 bowl. The figure quoted in a listing is the minimum base unit width needed to house the bowl, overflow, waste and tap connections, not the outside dimension of the sink itself. Always measure inside your own cabinet.
