Specify Surface Treatment Before Quotation
Coordinate coating, masking, final dimensions and verification in a machining project.
Why “Anodized” or “Plated” Is Not a Complete Requirement
A treatment name leaves important choices unresolved: substrate, process specification, thickness, masking, appearance and final acceptance. Agree them while the machining route is being priced, so the factory and treatment partner work toward the same finished part.
This guide concerns requirement planning. It is not a treatment qualification, test report or promise that every material/process combination is available.
Define Function Before Appearance
Identify surfaces that locate, seal, slide or conduct electricity separately from cosmetic faces. Explain the environment and required function, then specify the applicable process standard/type, coating system and thickness where relevant. Material grade and condition remain part of the requirement; a coating cannot substitute for an undefined substrate.
For appearance, agree color and texture references, cosmetic zones, allowable contact/rack marks and viewing conditions. For polishing, a mirror-like photograph is not itself a quantitative surface-roughness specification. State the parameter and test requirement if one is needed.
Which Dimensions Apply After Treatment?
Mark critical bores, threads, bearing seats and locating faces, and specify the stage at which their dimensions apply. The Aluminum Anodizers Council notes that anodizing changes dimensions and that alloy, process conditions and pretreatment affect the result. It recommends consultation with the actual anodizing plant. A universal machining allowance should not replace that discussion.
Coordinate masking and rack/contact positions before manufacture. Decide whether a fit is machined to its final size before treatment, masked during treatment or finished afterward. The agreed sequence must be consistent with both the drawing and treatment requirements; a shop cannot silently adjust the design to solve a coating problem.
Heat Treatment and Final Sizing
Specify material condition, required treatment, final hardness and test method. Include case depth or other characteristics when required by the design. Review possible dimensional change, stock reserved for grinding and the final inspection stage with the manufacturing and heat-treatment partners.
For centerless or other grinding, define the surfaces, final size, form/runout and roughness requirements. Do not assume a hardening operation automatically includes finish grinding or that a hardness reading verifies every treatment requirement.
Specify Evidence and Handling
Request treatment-lot records, certificates or specified tests at quotation. If coating thickness, adhesion, corrosion testing or hardness records are needed, agree the exact method, location, sampling and report with the proposed partner. Requirements that have not been verified cannot be presented as guaranteed services.
After final inspection, define cleaning, preservation, part separation and packaging. Cosmetic and functional surfaces may require different protection. Connect the treatment lot and reports to the shipped lot so that any issue can be traced.
Before Releasing the Order
Confirm substrate and condition; process specification; thickness/hardness; treated versus masked zones; final-size stage; appearance reference; reports/tests; and packaging. See finishing and heat-treatment scope and inspection planning.
Technical Reference
Aluminum Anodizers Council: Anodizing FAQ provides general guidance on dimensional effects and masking. Project allowances must be confirmed with the actual treatment partner.