Materials

Duplex Stainless Steel

High strength, marine & chemical.

2205 · 2507

Carbon Steel

Structural & general engineering.

Q235 · Q345 · 45#

Aluminum

Lightweight, formable.

5052 · 6061 · 6063

Titanium

Ultra-light, corrosion-resistant.

TA1/TA2 · TC4

Copper

Conductive, decorative.

T2 · H62 · B10

Surface treatment & finishing

Specify the finish, not just the name.

15 technical guides covering mill finishes, mechanical and chemical treatments, roughness measurement, drawings, welds and acceptance evidence.

Guides: 15
Words: 48k+
Topics: 3

Finish selection

Mill delivery conditions and appearance-led finishes, separated from unsupported roughness or performance assumptions.

Inspector comparing stainless samples with different surface finishes.

01 15 min

Surface finishes: buyer guide

A stainless-steel finish is the combined result of the substrate, mill route, mechanical or chemical treatment, and subsequent handling. Names such as 2B, bright annealed, brushed, mirror, blasted, pickled, passivated, and electropolished describe...

Stainless strip passing through finishing rollers in a mill.

02 12 min

2B stainless finish

2B is a cold-rolled stainless-steel mill finish, not a mechanical polishing grade. In common production language, it follows annealing and descaling or pickling and includes a light final rolling pass that produces a relatively smooth, moderately...

9 refsRead

Reflective stainless strip exiting a controlled-atmosphere annealing line.

03 13 min

BA bright-annealed finish

BA means bright annealed. In common stainless-steel production language, it identifies a cold-rolled surface annealed under controlled conditions intended to limit heavy surface oxidation and preserve a bright rolled appearance. BA is usually...

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Stainless panel receiving a directional brushed finish on a belt machine.

04 12 min

No.4 brushed finish

No.4 is best treated as a family of directional, mechanically finished stainless-steel surfaces, not as a universal grit recipe. The name indicates a satin appearance with visible linear lay, but it does not by itself fix the starting surface, abrasive...

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Technician polishing a reflective stainless surface in a controlled cell.

05 13 min

Mirror polishing

Mirror polishing is a sequence of surface preparation and progressively finer mechanical finishing intended to reduce visible line structure and produce a clear reflected image. “Mirror” is not one universal technical grade. A part may be bright yet show...

Operator bead blasting a stainless enclosure inside a closed cabinet.

06 14 min

Bead-blasted finish

Bead blasting propels controlled media against stainless steel to clean, texture, or visually homogenize the surface. The result is commonly matte or low-glare and lacks the deliberate linear grain of a brushed finish. “Bead blasted” is not a complete...

Treatment processes

Mechanical, chemical, electrochemical and coating routes with their process variables and hard limits.

Stainless pipe spools on a controlled chemical-treatment and rinse rack.

07 16 min

Pickling and passivation

Pickling and passivation are related but different chemical treatments. Pickling removes heat tint, embedded contamination, and some oxide or metal from the surface. Passivation follows thorough cleaning and promotes a clean, chromium-enriched passive...

08 17 min

Electropolishing

Electropolishing removes stainless steel electrochemically. The part is made anodic in a controlled electrolyte, and metal is dissolved from the surface under conditions intended to produce smoothing, brightening, and a clean passive condition. The process...

09 17 min

Magnetic abrasive finishing

“Magnetic polishing” usually refers to magnetic abrasive finishing (MAF): a magnetic field holds and controls a flexible mass of ferromagnetic carrier particles and hard abrasive near a stainless-steel surface while relative motion produces micro-cutting,...

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Technician applying powder coating to a grounded stainless frame.

10 18 min

Powder coating stainless

Stainless steel can be powder coated, but the alloy’s corrosion resistance does not make surface preparation optional. A durable system depends on a clean, reproducible substrate; a pretreatment qualified for the grade and starting finish; powder chemistry...

Technician blending a stainless TIG weld seam with controlled extraction.

15 19 min

Weld-seam finishing

Weld-seam finishing is not one operation. It can include removal of spatter and sharp projections, blending or retaining the weld profile, matching a directional or polished finish, removing heat tint and oxide, cleaning residues, and restoring a suitable...

Specification & acceptance

Measurement, standards translation, drawing callouts and application-specific acceptance planning.

Stylus profilometer measuring a brushed stainless coupon.

11 15 min

Surface roughness Ra

Ra is the arithmetic mean height of a filtered profile, not a complete description of a surface. A defensible requirement identifies the parameter and limit, the governing standard and edition, the filter and evaluation conditions, the measurement...

Engineer comparing stainless finish samples beside generic standards binders.

12 14 min

ASTM, EN, JIS and GB finishes

ASTM, EN, JIS, and GB finish codes are not a multilingual dictionary. Their standards cover different product scopes, editions, manufacturing routes, optional requirements, and acceptance conventions. Similar-looking labels or descriptions may identify a...

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Engineer comparing a stainless part with a drawing and finish comparator.

13 14 min

Finish callouts on drawings

A surface-texture symbol is a pointer into a measurement contract, not the whole contract. For a new ISO drawing, identify the applicable ISO 21920 edition and fully define the profile parameter, limit, units, specification operator, direction, and...