{"id":28948,"date":"2026-09-08T15:05:21","date_gmt":"2026-09-08T07:05:21","guid":{"rendered":"https:\/\/wanzhisteels.com\/?p=28948"},"modified":"2026-09-08T15:05:22","modified_gmt":"2026-09-08T07:05:22","slug":"stainless-steel-surface-finish-guide","status":"publish","type":"post","link":"https:\/\/wanzhisteels.com\/zh\/stainless-steel-surface-finish-guide\/","title":{"rendered":"Stainless steel surface finish guide"},"content":{"rendered":"

Pick the wrong surface finish on a stainless steel order and you can end up with a sheet that looks right in the catalogue but fails on the shop floor. The three names buyers ask about most are 2B, No.4 and BA. They sound close, yet they are made differently, look different, and suit different jobs.<\/p>\n\n\n\n

Wanzhi Group has rolled, finished and exported stainless steel for 15 years across more than 100 countries. This guide explains what each finish is, how it is produced, what it costs, and how to choose between them without guesswork. If you only read one section, read the comparison table near the middle.<\/p>\n\n\n\n

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\"Three
2B Surface<\/figcaption><\/figure>\n<\/div>\n\n\n\n
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\"stainless
NO.4 Surface<\/figcaption><\/figure>\n<\/div>\n\n\n\n
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\"stainless
BA Surface<\/figcaption><\/figure>\n<\/div>\n<\/div>\n\n\n\n

What a surface finish is, and why it matters<\/h2><\/div>\n\n\n\n

A surface finish is the final state of the steel face after rolling and any extra treatment. It is not a coating. The alloy underneath stays the same, so a 304 sheet is still 304 whether it leaves the mill at 2B or gets polished to No.4 afterward.<\/p>\n\n\n\n

What changes is the texture, the reflectivity, and how the sheet behaves in fabrication and service. Finish affects fingerprint visibility, how scratches read, how easy the part is to clean, and what it costs to make. On a food tank the finish is a hygiene issue. On a lift door it is mostly a looks issue. Same metal, different priorities.<\/p>\n\n\n\n

The three finishes at a glance<\/h2><\/div>\n\n\n\n
Finish<\/th>How it is made<\/th>Look<\/th>Common use<\/th><\/tr><\/thead>
2B<\/strong><\/td>Cold rolled, annealed, pickled, light final pass<\/td>Dull, slightly cloudy grey<\/td>Industrial tanks, general fabrication, base for further polishing<\/td><\/tr>
No.4<\/strong><\/td>2B base run through abrasive belts<\/td>One-direction satin grain<\/td>Kitchens, elevators, architecture, food equipment<\/td><\/tr>
BA<\/strong><\/td>Cold rolled then bright annealed in controlled atmosphere<\/td>Smooth, mirror-like, reflective<\/td>Decorative trim, automotive, appliances, medical<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

These three cover most orders. The rest of this guide breaks each one down, then puts them side by side.<\/p>\n\n\n\n

2B finish<\/h2><\/div>\n\n\n\n

2B is the default mill finish for cold-rolled stainless sheet and coil. After cold rolling, the steel is annealed (softened by heat) and pickled (acid cleaned to remove scale), then given a light pass through polished rolls. That last pass is what gives 2B its name.<\/p>\n\n\n\n

The surface is smooth but not shiny. It reads as a soft, grey, slightly cloudy face. You will not see a clear reflection in it. Roughness typically sits around Ra 0.1 to 0.5 micrometres.<\/p>\n\n\n\n

2B is the workhorse finish. Most stainless that gets welded, formed, or polished later starts as 2B, because it is the cheapest finished state and the best base for further work. We supply 2B in 304, 316L and other grades<\/a> as coil and sheet, and it is the feedstock for our brushed stainless steel sheet<\/a> line.<\/p>\n\n\n\n

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\"2B
2B surface finish<\/figcaption><\/figure>\n<\/div>\n\n\n\n
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\"BA
BA surface finish<\/figcaption><\/figure>\n<\/div>\n<\/div>\n\n\n\n

No.4 finish<\/h2><\/div>\n\n\n\n

No.4, often called brushed or satin, starts from 2B and adds an abrasive-belt pass in one direction. The belt grit (usually 150 to 240) lays down short, parallel grain lines. The result is a soft sheen that scatters light instead of mirroring it.<\/p>\n\n\n\n

No.4 hides fingerprints and light scratches far better than a polished or 2B face, which is why it dominates commercial kitchens, hospital equipment, elevator cabins and architectural trim. Roughness runs about Ra 0.2 to 0.8 micrometres.<\/p>\n\n\n\n

A close cousin is Hairline (HL), which uses a finer, longer grain for a more formal look in luxury interiors. We cover both in our brushed stainless steel sheet product page<\/a>. After brushing, the sheet is usually passivated to rebuild the chromium layer the belt may have disturbed, which matters most on 316L used in marine and chemical service<\/a>.<\/p>\n\n\n\n

BA finish<\/h2><\/div>\n\n\n\n

BA stands for bright annealed. Here the cold-rolled steel is annealed in a tightly controlled, oxygen-free (usually hydrogen) atmosphere so no scale forms and no pickling is needed. The hot steel self-anneals against a bright, smooth roll, and the surface comes out smooth and reflective, closer to a mirror than 2B but less perfect than an 8K polish.<\/p>\n\n\n\n

BA is picked when appearance matters and a reflective, clean face is wanted without the cost of full mirror polishing. It shows up in decorative trim, automotive trim, appliances, and medical parts. It also carries a smoother, less contoured surface than 2B, which some fabricators like for deep drawing.<\/p>\n\n\n\n

One caveat worth knowing: BA can show handling marks more than 2B because there is no grain to break them up, and it is not as scratch-forgiving as No.4.<\/p>\n\n\n\n

2B vs No.4 vs BA: the side-by-side comparison<\/h2><\/div>\n\n\n\n

This is the table most buyers come for. Save it or send it to your procurement team.<\/p>\n\n\n\n

Feature<\/th>2B<\/th>No.4<\/th>BA<\/th><\/tr><\/thead>
How it is made<\/td>Cold roll, anneal, pickle, light pass<\/td>2B plus abrasive belt in one direction<\/td>Cold roll, bright anneal in controlled atmosphere<\/td><\/tr>
Appearance<\/td>Dull grey, cloudy, no reflection<\/td>Satin grain, low sheen<\/td>Smooth, bright, near-mirror<\/td><\/tr>
Roughness (Ra)<\/td>0.1 to 0.5 \u00b5m<\/td>0.2 to 0.8 \u00b5m<\/td>0.05 to 0.2 \u00b5m<\/td><\/tr>
Reflectivity<\/td>Low<\/td>Low, scattered<\/td>High<\/td><\/tr>
Fingerprint visibility<\/td>Moderate<\/td>Low<\/td>High<\/td><\/tr>
Scratch hiding<\/td>Poor<\/td>Very good<\/td>Poor<\/td><\/tr>
Cleanability<\/td>Easy<\/td>Easy<\/td>Easy, but shows marks<\/td><\/tr>
Cost add over base<\/td>Baseline<\/td>+10 to 20%<\/td>+10 to 25%<\/td><\/tr>
Best for<\/td>Tanks, fabrication, base for polish<\/td>Kitchens, lifts, architecture, food gear<\/td>Decorative trim, appliances, medical<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

There is no “best” finish here. There is only the one that fits the job. A brewery tank wants 2B or No.4 on the inside for cleanability. A lift door wants No.4 to hide scratches. A shopfront trim wants BA for shine.<\/p>\n\n\n\n

\"Macro
finish surface macro display<\/figcaption><\/figure>\n\n\n\n

Other finishes you will meet<\/h2><\/div>\n\n\n\n

Three names come up often enough to know:<\/p>\n\n\n\n