Appearance
Reference sample, cosmetic zones, color/gloss/texture criteria and agreed viewing conditions.
Functional & visual
Surface Finishes for Precision Metal Parts
Select finishes for corrosion protection, wear, appearance, conductivity and identification.
Start with the application
Define the Material and Purpose
Review the finish against the actual grade, material condition and manufacturing route. Cast and machined surfaces may require different preparation and acceptance planning.
- Substrate & state
- Exact material grade, condition, cast or machined surface and any existing treatment.
- Service environment
- Exposure media, temperature, handling and relevant operating conditions.
- Functional purpose
- Corrosion, wear, friction, electrical behavior, cleanliness or identification requirements.
- Appearance
- Color, gloss, texture, cosmetic zones and the proposed reference sample.
Compare the requirements
Explore Surface Finish Options
Expand an option to review its requirements. Suitability, preparation, process specification and acceptance are confirmed for the selected material and function.
Surface State & Mechanical Treatments
As machined
Tool marks and edge condition remain visible; define roughness only where function requires it.
Confirm the exact substrate and surface state, applicable specification, protected areas and required acceptance checks.
Review this finish →Bead blasted
A matte mechanical texture that needs agreed media, coverage, masking, and cosmetic limits.
Confirm the exact substrate and surface state, applicable specification, protected areas and required acceptance checks.
Review this finish →Polishing and brushing
Direction, texture, edge treatment, cosmetic zones, and reference samples should be agreed before production.
Confirm the exact substrate and surface state, applicable specification, protected areas and required acceptance checks.
Review this finish →Conversion & Chemical Treatments
Anodized aluminum
Specify alloy, pretreatment, coating type, color, thickness, sealing, masking, and acceptance.
Confirm the exact substrate and surface state, applicable specification, protected areas and required acceptance checks.
Review this finish →Conversion coating
Often considered for corrosion protection, paint preparation, or controlled electrical contact behavior.
Confirm the exact substrate and surface state, applicable specification, protected areas and required acceptance checks.
Review this finish →Passivation
For applicable stainless steels, specify the governing treatment, cleaning state, protected areas, and verification method.
Confirm the exact substrate and surface state, applicable specification, protected areas and required acceptance checks.
Review this finish →Coating Systems
Powder coating
Define pretreatment, color and gloss range, film build, masking, adhesion, and cosmetic zones.
Confirm the exact substrate and surface state, applicable specification, protected areas and required acceptance checks.
Review this finish →Wet painting
Define the coating system, preparation, color and gloss, cure, masking, adhesion, and environmental exposure.
Confirm the exact substrate and surface state, applicable specification, protected areas and required acceptance checks.
Review this finish →Plating
Specify the substrate, coating system, thickness, undercoat, masking and tests. Review hydrogen embrittlement and heat-treatment requirements where applicable.
Confirm the exact substrate and surface state, applicable specification, protected areas and required acceptance checks.
Review this finish →Identification
Laser marking
Define content, location, contrast, permanence, serialization or lot data, and protected functional surfaces.
Confirm the exact substrate and surface state, applicable specification, protected areas and required acceptance checks.
Review this finish →Not sure which option fits? Submit the material and functional requirements for review →
Mark the functional surfaces
Plan Masking, Build and Interfaces
Identify treated and protected regions, and define whether dimensional and functional acceptance applies before or after treatment.
- 1. Threads: identify protected or treated surfaces and gauging requirements.
- 2. Fit bore: define allowable build and the required delivered fit.
- 3. Sealing face: identify the finish boundary and functional acceptance.
- 4. Electrical contact: mark the required surface condition and verification.
- 5. Cosmetic face: specify color, gloss, texture and appearance zones.
- 6. Hanging location: agree permitted contact marks and protected regions.
Agree what will be accepted
Appearance and Functional Checks
Thickness & dimensions
Applicable thickness or class, measurement locations, protected areas and acceptance before or after treatment.
Functional tests
Drawing-required adhesion, corrosion, electrical or other tests with agreed method, conditions and limits.
Release evidence
Sample approval, inspection stage, sampling scope, requested reports and traceable identification.
From Substrate Review to Protected Delivery
- 1Confirm substrate and finish requirements
- 2Plan preparation and masking
- 3Agree sample acceptance where required
- 4Control the specified treatment process
- 5Verify appearance and functional requirements
- 6Protect, identify and package the parts
Detailed finish requirements & anodizing reference
Finish Requirements
Surface finishing can address corrosion, abrasion, friction, conductivity, appearance, identification, cleanliness, or preparation for assembly. The base material and manufacturing process affect the result.
Finish Process Controls
Call out the finish standard, type or class, thickness where relevant, color and gloss range, cosmetic zones, masking, electrical contact areas, threaded features, sealing faces, sample approval, and test method.
Coating Thickness & Appearance
Coating can change fits, edge condition, hole size, electrical continuity, and visual consistency. Alloy, surface preparation, casting texture, machining marks, and lot-to-lot variation should be reviewed before quotation.
Finishing & Assembly
Masking, coating build, grounding points, sealing faces, threaded features and cosmetic handling must remain compatible with the product assembly sequence and functional checks.
Anodizing reference
The Aluminum Anodizers Council notes that alloy and temper, mechanical preparation, chemical preparation, and anodic oxide type all affect an anodized result.
See the Aluminum Anodizers Council guidance on specifying anodized aluminum.
What belongs in a complete finish specification?
Include the governing specification, type or class, thickness where applicable, preparation, color and gloss range, masking, cosmetic zones, sample approval and required tests.
Should dimensions apply before or after finishing?
State this on the drawing, especially for fits, threads, sealing faces and electrical contacts. Coating thickness and masked areas must be considered when defining the final dimensions.
Can cast and wrought aluminum use the same anodized finish?
The alloy, temper and surface preparation affect the result. Review the specific substrate with the finishing team and agree representative samples when appearance is important.
Engineering resources
Prepare the Finish and Inspection Plan
How to Select a Surface Finish for Metal Parts
Select and specify finishes for cast and machined parts using material compatibility, service conditions, functional requirements and appearance criteria.
Read engineering guide →Building a Practical Inspection Plan for Cast and Machined Parts
Translate drawing requirements and product risk into incoming checks, first-article inspection, in-process controls, final verification and shipment records.
Read engineering guide →RFQ Checklist for Die Casting, CNC Machining, and Assembly
A complete RFQ checklist covering engineering files, revisions, demand, materials, critical features, finishing, inspection, assembly, and delivery.
Read engineering guide →Project Planning Notes
Finish selection
Surface Finish Selection
Protection, appearance, wear, conductivity, sealing, identification, and assembly interfaces must be specified together.
- Purpose and substrate
- State the base alloy and whether the finish is for corrosion, wear, appearance, electrical behavior, thermal performance, or identification.
- Preparation and build
- Define cleaning, blasting or polishing, pretreatment, coating type, thickness or class, cure, and allowable dimensional build.
- Masking and appearance
- Mark threads, sealing faces, grounding contacts, fits, hanging points, cosmetic zones, color, gloss, and texture references.
- Acceptance criteria and tests
- Agree sample approval, visual conditions, thickness, adhesion, corrosion, conductivity, marking, or other drawing-required tests.
Production Release Workflow
- Finish requirement
- Substrate review
- Preparation plan
- Masking plan
- Process control
- Visual & functional checks
- Protected handling
Material & finish review
Review Your Finish Requirements
Send the finish callout or explain the required function. The selected finish can be edited in the inquiry before submission.
Include with your RFQ
- Drawing revision, exact material and surface condition.
- Finish specification, type/class and thickness requirements.
- Color, gloss, texture or reference sample; cosmetic zones.
- Masking drawing, fits, threads, seals and electrical contacts.
- Service conditions, test methods, acceptance limits and reports.
- Quantities, schedule and protected handling or packaging needs.