Material and finish decisions are the ones that fail latest and cost the most to reverse. The grade can be right and the geometry can be right, and the part can still come back in three years with rust creeping from a cut edge — or arrive a shade different from the batch before it. This cluster covers choosing the base metal, choosing the coating system, and writing down what 'the same colour' means before the first batch is made.
What this cluster covers
Material selection comes first and is an environment question before it is a price question; the stainless-versus-carbon-steel article is framed that way, and the certificate article explains what heat traceability actually buys you when a batch is questioned later. The coating group covers system choice (powder against liquid, by volume, colour and performance), diagnosis (which defect points at which cause, and who owns the fix), and the practical details that decide whether the coating reaches the whole part — hang points, vent and drain holes, and masking. Two finishes have their own articles: aluminium anodising and stainless surface finish, plus the passivation and weld cleanup that stainless needs after welding. The last group is specification: cosmetic surface classes, and low-carbon or recycled content when a customer is asking for CBAM or EPD evidence.
Where to start
- Choosing a base metal: start with the selection guide, then the stainless comparison if the part sees coastal, food or chemical exposure.
- Choosing a coating: start with the finishing overview, then powder versus liquid for your volume and colour requirements.
- Something has already gone wrong on a coated part: the defect article is organised by root cause, so it works backwards from the symptom.
- Writing the requirement down: the cosmetic surface class article is where a finish requirement belongs on a drawing, and it is the cheapest argument you will ever prevent.
Base material and traceability
Sheet Metal Material Selection Guide | SanJun Hardware
How to choose the right sheet metal material — cold-rolled steel, stainless steel or aluminum — plus gauge, cost and finish tips for enclosures and cabinets.
Stainless Steel vs Carbon Steel Enclosure: How to Choose
Stainless vs carbon steel enclosures: lifecycle cost, 304 vs 316 grade choice, environmental fit and a 5-mistake checklist for B2B buyers.
EN 10204 3.1 vs 3.2: Certificates & Heat Traceability
EN 10204 3.1 vs 3.2 explained: who validates each certificate, what test data it contains, where heat traceability breaks and what to require before cutting.
Pretreatment Before Powder Coating: An Enclosure Buyer's Guide
What each of the five washer stages actually does, how to choose between iron phosphate, zinc phosphate and zirconium for a mixed-metal assembly, the enclosure geometries that trap treatment solution, and the questions that tell you more than a certificate.
Coating systems and diagnosis
Sheet Metal Surface Finishing: Powder Coating & Anodizing
How to choose a sheet metal surface finish — powder coating, anodizing, plating and passivation compared, with pretreatment, drawing specs and verification.
Sheet Metal Powder Coating vs Liquid Painting Guide 2026
Powder coating vs liquid painting for sheet metal enclosures: 5-row comparison matrix, 5 cost drivers, 6 failure modes, 12-point DFM checklist, 3 OEM cases.
Powder Coating Defects: Causes, Fixes and Who Owns Them
Powder coating defects: does the defect follow the part or the batch? That answer sorts geometry, substrate, cure and contamination causes, and who owns them.
Sheet Metal Powder Coating: Hang Points, Vents & Masks
Design sheet metal for the powder line: hang points, drain and vent holes, Faraday cage reach, masking callouts and galvanizing vent rules, with drawing notes.
Powder Coating Colour Match: RAL, Gloss and Batch Consistency
Why two batches under one RAL code still differ: RAL as reference versus specification, delta E with its five conditions, gloss at 20/60/85°, film build, cure, reclaim ratio, limit samples and a paste-ready specification block.
Special finishes
Sheet Metal Aluminum Anodizing Complete Guide 2026
Aluminum anodizing guide for sheet metal enclosures: Type I/II/II-B/III hard anodizing, AAMA 611, MIL-A-8625 specs, 6-row comparison and 7 DFM rules.
Stainless Steel Sheet Metal Surface Finish Guide
Stainless steel sheet metal surface finish guide: 2B, BA, No.4, No.8, hairline — Ra values, ASTM A480, applications for OEM enclosures.
Stainless Steel Passivation: ASTM A380 vs A967 Guide
Stainless steel passivation guide for enclosures: clean and descale welds, compare citric and nitric acid, cite ASTM A967 and choose a verification test.
Specification and declared content
Sheet Metal Cosmetic Surface Classes: A to E Guide
Specify cosmetic surface classes on sheet metal: zone the drawing, set defect limits by size, count and spacing, match the finish, settle disputes with samples.
Low-Carbon Steel Enclosure: CBAM, EPD & Recycled Content
Low-carbon steel enclosures: route CO2e ranges, recycled content vs scrap ratio, the EPD fields to request, where EU CBAM stands in 2026, and ESPR and DPP.