Drawing-Based Custom Manufacturing
Surface Finishing for Custom Metal Parts
Surface finishing changes how a part looks and behaves in use. Anodizing grows an oxide layer on suitable aluminum; powder coating adds a colored film; mechanical preparation changes texture. JUNCHU coordinates the treatment with the base material, visible faces, mating features and final acceptance requirements.
Anodizing · Coating
Texture · Marking
PART TYPES
Material-Compatible
Finish Selection
MATERIAL ROUTES
Masking · Marking
Protection · Packing
RELATED REQUIREMENTS
Substrate · Texture
Masked Surfaces
FINISH INPUTS
Finish Families & Their Uses
Choose protection, appearance or function
A finish should solve a defined requirement. The same treatment can behave differently on different alloys, surface conditions and part geometries.
Anodizing
PROCESS & PROJECT REVIEW
Anodizing converts the surface of suitable aluminum into an oxide layer. It is used for protection, appearance and, with a suitable specification, wear-related requirements. Alloy, pretreatment, dye and sealing affect the result. Decorative and hard-anodized requirements should be specified separately; color and dimensional behavior are not identical.
01
Powder Coating
PROCESS & PROJECT REVIEW
Powder coating creates an opaque polymer film with a selected color, gloss and texture. It is commonly considered for covers, frames and fabricated enclosures. Pretreatment and service exposure affect durability. Coating thickness can interfere with threads and sliding fits, so mask critical areas and review rack-contact locations.
02
Pretreatment & Other Finishes
PROCESS & PROJECT REVIEW
Brushing, polishing and blasting create different textures rather than a single interchangeable finish. Stainless passivation addresses surface contamination and corrosion behavior; plating deposits a specified metal layer on a suitable substrate. Laser marking adds identification and needs its own contrast, location and durability requirements. Confirm the exact treatment in the project scope.
03
Before Manufacturing
What We Review Before Quotation
Agree the requirements below before committing to tooling, processing or a production batch.
01
Base Material
State the alloy and condition; finish compatibility depends on the substrate.
02
Finish Specification
Identify the treatment type, applicable specification and thickness if required.
03
Color & Texture
Use a color reference and, for critical appearance, an approved physical sample.
04
Masking & Contact Areas
Mark threads, mating fits, electrical contacts and surfaces that must stay untreated.
05
Cosmetic Acceptance
Agree viewing conditions, visible zones and acceptable color or texture variation.
06
Packing & Records
Specify scratch protection, batch identification and any required test or finish records.
Finishing by Part Function
Define what the finished surface must do
01
Cosmetic Housings
Define visible faces, color, gloss, grain direction and viewing conditions. An approved physical sample helps align appearance expectations.
02
Fits & Threads
Coating build or surface conversion can affect clearance. Identify dimensions that apply after treatment and the areas requiring masking.
03
Electrical Contact Areas
A decorative or protective layer may reduce electrical contact. Mark grounding, bonding and contact faces on the drawing.
04
Marks & Handling
Specify mark content, position and orientation. Protect finished surfaces with suitable separation and packing materials.
Start Your Surface Finishing Project
Start with the part requirements, review the manufacturing route, then agree inspection and delivery before production.
Specify the Finish
Send the base material, finish type, color reference, visible zones and dimensions that must hold after treatment.
Approve a Reference
For appearance-sensitive parts, agree a sample, masking plan and acceptable variation before processing the batch.
Check the Result
Check the agreed visual criteria, masked surfaces and finished fits. Required thickness or other test records must be specified.
Protect for Delivery
Separate cosmetic faces and protect edges and contact areas. Agree packaging that suits the finished surface.
Project Planning
Planning Finishing & Appearance Approval
Treat surface preparation, dimensional effects and visual acceptance as separate requirements.
Choose by Substrate and Function
Start with the exact material grade and exposure conditions. Anodizing, powder coating, plating and passivation serve different purposes and have different substrate requirements. Define whether the priority is appearance, wear, corrosion protection, electrical contact or a combination before selecting the specification.
What Drives Finishing Cost
Part size, batch quantity, surface preparation, masking complexity and handling requirements affect price. Deep recesses, mixed cosmetic zones and special racking requirements may need extra review. Specify required test records explicitly; a finish name by itself does not define thickness, performance or inspection scope.
Approve a Meaningful Reference
Use the intended alloy, preparation and geometry when evaluating an appearance sample. A flat color chip may not predict the appearance of machined edges, welds or deep pockets. Agree the reference sample, viewing conditions, acceptable variation and any permitted fixture or contact marks before production.
Check and Protect Finished Parts
Identify dimensions and threads that must comply after treatment, together with masked areas and their boundaries. Agree required coating measurements or tests and how results will be recorded. Plan separation and clean handling so the accepted surface is protected during assembly, storage and shipment.
Component images are 3D concept illustrations of representative parts.
Before You Start Your Project
Common Questions
Before an RFQ
Review the information needed for a clear quotation, practical process planning and agreed inspection requirements.
How should I specify a surface finish?
State the finish type, color reference, texture, cosmetic surfaces and areas that must remain untreated. For appearance-sensitive parts, agree on a physical sample and acceptance conditions. Coating thickness, alloy and pretreatment can affect dimensions and color; review these together with the drawing.
Will anodized colors match exactly between batches?
Color depends on alloy, material condition, pretreatment, processing and viewing conditions. Use an approved sample and an agreed acceptance range for appearance-critical orders; a color name alone may not define an adequate match.
Can threads and contact faces be masked?
Mark the relevant areas on the drawing and define which features must remain untreated. Masking method and edge transitions need review alongside coating thickness and the required fit.
Can a finish be selected for any material?
Finishes are substrate-dependent. Anodizing is generally associated with aluminum, while plating and passivation require suitable materials and process specifications. Confirm compatibility and any required test evidence for the actual grade.
How should finish acceptance and protective packing be defined?
Record the treatment specification, base material, approved appearance reference and visible zones. Identify allowed contact marks, masking boundaries and dimensions that apply after treatment. Specify required coating measurements or test records, together with viewing conditions for cosmetic checks. Agree clean handling and separation so accepted surfaces remain protected through assembly and shipment.
Match Surface Treatment to Function and Acceptance
| Requirement | Define before quotation | Review during sample approval |
|---|---|---|
| Appearance | Visible faces, texture, color and a suitable reference | Compare representative parts under agreed viewing conditions. |
| Mating fit | Final dimensions, masking and contact areas | Check the treated components and actual mating interfaces together. |
| Exposure or performance | Substrate, operating environment and required test method | Evaluate the agreed evidence rather than assuming performance from finish name alone. |
| Handling and delivery | Contact points, surface protection and packing | Confirm that the packing protects the accepted cosmetic and functional zones. |
Keep treatment and substrate linked
A finish suitable for one material may not be appropriate for another. Review pretreatment, base material and the exact finish specification together; color alone does not define the complete treatment or acceptance scope.
Use the RFQ checklist to bring these decisions into one controlled enquiry package.
Ready To Start Your Project?
Start With Your Drawings - or Tell Us What You Need
Share drawings, photos or sketches with your quantity, material, finish and target date. We review the available information, clarify technical requirements and confirm quotation timing. Complex or multi-process projects may require additional review.
Discuss confidentiality and NDA requirements before sharing sensitive project files.