Are these Ra values guaranteed for every coil or sheet?

No. These are typical ranges only. Real Ra depends on mill, polishing parameters, grit size, and measurement direction. Confirm with mill data or actual Ra testing for critical jobs.

Can 2B and BA overlap in Ra?

Sometimes ranges can overlap, but BA is usually smoother and more reflective, while 2B is smooth and slightly reflective but not mirror-like.

Is No.4 always within the same Ra range?

Not always. Grit, line speed, and process settings can change Ra. Use typical ranges as a reference and confirm if the spec is strict.

Surface Finish Chart

Surface Finish Chart · 2B / BA / No.4 / HL / 8K vs Ra

Quick reference for stainless steel sheet/plate finishes and typical surface roughness (Ra). Use for purchasing, quoting, and specification alignment.

LYHSteel · Steel Calculators

Finish → Roughness (Ra)

Select a finish

Typical Ra (µm)

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Approx. Ra (µin)

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Typical usage & notes

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Directional finishes (No.4/HL) may vary by grit, line speed, and measurement direction.

Disclaimer: Ra ranges are typical values only. Always confirm with mill datasheets, surface measurements, or project specifications for critical applications.

Target Ra → Likely Finishes

Enter Ra value

Unit

Likely finishes (approx.)

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Enter a target Ra to see finishes that typically match or come close.

Converted Ra

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Shown in both µm and µin for international specs.

Practical reminder

Confirm with actual test data

Especially for food/pharma/architectural panels where Ra is a formal requirement.

How to use: If a drawing says “Ra ≤ 0.4 µm”, enter 0.4 µm to see which finishes usually fall near that range, then align the finish name in your PO.

Stainless Steel Surface Finish Chart (LYHSteel)

When a customer says “2B” or “No.4”, they are often describing a combination of appearance, cleanability, and roughness (Ra). This page helps you connect common stainless finishes to typical Ra ranges so you can specify, quote, and purchase more consistently.

Typical Ra Ranges for Common Stainless Finishes

Mobile tip: swipe left/right to view the full table.

Finish	Process / Appearance	Typical Ra (µm)	Typical Ra (µin)	Typical applications
No.1	Hot rolled, annealed & pickled; matte/rough	2.5 – 6.3	100 – 250	Heavy plate, structural parts, high-temp components
2D	Cold rolled, annealed & pickled; dull, non-reflective	0.8 – 2.0	30 – 80	General engineering, non-decorative parts
2B	Cold rolled, skin passed; smooth, slightly reflective	0.2 – 0.5	8 – 20	Tanks, enclosures, kitchen equipment, general sheet
BA	Bright annealed; reflective, decorative baseline	0.05 – 0.2	2 – 8	Appliances, architectural panels, decorative parts
No.4	Brushed / satin; short, uniform grain	0.4 – 0.8	15 – 30	Appliance fronts, elevators, trims, wall panels
HL	Hairline; long directional grain	0.5 – 1.0	20 – 40	High-end decoration, doors, strips, feature panels
8K / No.8	Mirror polish; highly reflective	0.01 – 0.05	0.4 – 2	Mirrors, signage, luxury décor, premium displays

How to Choose the Right Finish

Food / hygiene: smoother surfaces are easier to clean; common choices include 2B, BA, and polished finishes.
Architectural / decorative: focus on visual consistency; No.4/HL provide brushed texture, BA/8K provide high reflectivity.
Structural / high-temperature: function first; No.1 and 2D are widely used as economical base finishes.

LYHSteel Supply & Processing Support

If your project requires finish control, LYHSteel can support sheet/coil supply and secondary processing workflows. For sourcing and quotations, you can reference the pages below.

Stainless Steel Sheet & Plate Stainless Steel Strip & Coil Surface Finishing Services All Products Contact Us

Keyword Synonyms

stainless steel surface finish chart, surface roughness Ra chart, 2B finish Ra, BA finish roughness, No.4 brushed finish, hairline finish HL, 8K mirror finish, stainless sheet finish guide, finish to Ra converter, Ra to finish lookup