The finish decides how a stainless surface looks, how it cleans and how much it costs. 2B is the default for fabrication, BA for bright work, No.4 and HL for visible brushed faces, 8K for mirror. Here is what each one actually is, and what it costs to go up the ladder.
At a glance
| Finish | How it is made | Appearance | Roughness (Ra) | Best for | Cost index |
|---|---|---|---|---|---|
| No.1 | Hot rolled, annealed, pickled | Dull grey, matte | ≈ 2.0–4.0 µm | Industrial tanks, structural, parts to be machined | 1.0 |
| 2B | Cold rolled, annealed, pickled, skin-passed | Smooth, slightly reflective, uniform | ≈ 0.1–0.5 µm | Default for fabrication, food equipment, general sheet | 1.1–1.2 |
| BA | Bright annealed in a controlled atmosphere | Bright, mirror-like sheen, no pickling | ≈ 0.05–0.2 µm | Decorative, appliances, deep-drawn parts, reflectors | 1.3–1.5 |
| No.4 | Brushed with 150–180 grit abrasive | Visible directional grain, satin | ≈ 0.4–1.0 µm | Kitchen equipment, elevator panels, visible architecture | 1.3–1.4 |
| HL | Hairline, fine long-grain polishing | Fine continuous lines, low gloss | ≈ 0.2–0.6 µm | Appliance fronts, column cladding, lift doors | 1.4–1.5 |
| 8K | Mirror polishing to 8000 grit equivalent | Mirror, clear reflection | ≈ 0.02–0.05 µm | Decorative, signage, luxury interiors | 1.8–2.5 |
What the numbers mean
Ra is the average roughness of the surface in micrometres. Lower is smoother. It matters for two reasons: appearance, and cleanability. In food, dairy and pharma, a lower Ra means fewer places for bacteria to sit — which is why hygienic specifications often call out Ra ≤ 0.8 µm.
Note that 8K is not automatically the "best" finish for hygiene. A mirror surface shows every scratch and fingerprint, and the polishing compound itself can be a contamination risk. For most hygienic work, 2B or a controlled No.4 is the right answer.
How to choose
- Nobody will see it and it will be painted or covered? No.1 or 2B. Do not pay for polish you will never see.
- Visible, and you want a clean industrial look? 2B keeps cost down and is easy to keep clean.
- Visible, and you want the "brushed stainless" look people expect? No.4 for a visible grain, HL for a finer, quieter grain.
- Bright, reflective, appliance-like? BA — and it is usually cheaper than polishing to 8K.
- True mirror? 8K, and budget for protective film plus careful handling.
Practical notes buyers learn the hard way
- Grain direction matters. No.4 and HL are directional. On a facade, specify the grain direction or adjacent panels will not match in light.
- Film is not optional on 8K. Unprotected mirror surfaces scratch in transit and on site. Specify PVC film and remove it within six months.
- Polishing removes material. Aggressive 8K polishing on thin sheet (under 0.5 mm) can affect flatness. Ask for the thickness after polishing.
- Colour varies by lot. Two batches of the same finish can differ slightly. For a single visible elevation, order the whole quantity at once.
Bottom line
Specify the finish by where the part is seen and how it is cleaned, not by what sounds premium. 2B covers most fabrication; No.4/HL covers most visible architecture; 8K is for genuine mirror work and should be quoted with film and careful packing.
All finishes above are available on 0.3–3.0 mm cold rolled sheet and coil. See sheet and plate or send your finish requirement.
Have a question about stainless steel?
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