Machining for consumer electronics and lighting hardware
On a visible part, appearance is the specification. Colour consistency, a scratch-free face and a logo engraved in the right place decide whether the batch is accepted, long before anyone measures a dimension.
Part families
Aluminium shells for speakers, power banks, cameras and instruments. The visible faces carry a finish requirement, the internal faces carry the fit; conflating the two doubles the cost.
Thin rings and bezels where a 0.05 mm step is visible at arm's length and a colour difference between two batches is immediately obvious. These are planned as one dye lot per colour.
Milled fins with a controlled base flatness so the thermal interface actually contacts. Fin thickness and spacing are limited by the cutter, not by the thermal calculation, which is where designs often start.
Lamp bodies, heat spreaders and decorative rings. Anodized colour must match across a fixture set, and the thermal path usually needs a flat, unmasked contact area.
Fixtures for electronics assembly and inspection: plate flatness, pin positions and a non-marring surface where the product is touched.
Appearance specifications that can be inspected
| Requirement | How to write it | How it is verified |
|---|---|---|
| Colour | Pantone or RAL, plus dye lot tolerance | Approved sample, visual under D65 |
| Gloss | Gloss units at 60°, or "matte" | Gloss meter on a witness coupon |
| Surface texture | Brushed, bead blasted, polished, Ra range | Comparator plate or profilometer |
| Scratches | "No visible scratches on face A at 300 mm" | Visual inspection under defined lighting |
| Edge quality | 0.2–0.5 mm break, no burr | Touch and magnification |
| Marking | Logo file, depth, position tolerance | First article plus sample approval |
Finishing sequence for visible aluminium
Bead blasting after anodizing breaks the sealed oxide layer and leaves a patchy surface. The blast is a preparation step before the anodic layer is grown, never a repair after it.
An anodized thread will not take a mating screw without chasing, which removes the coating and the corrosion protection with it. Masking is quoted with the finish.
Laser engraving through the anodized layer gives a crisp, high-contrast mark. Engraving before anodizing fills the mark with oxide and loses the contrast.
Packing for a cosmetic part
A part that survives machining can still fail on arrival. Visible faces get a protective film, parts are separated rather than poured into a bag, and master cartons are sized so nothing shifts in transit. For anodized parts, foam or molded pulp separators prevent the abrasion that shows up as a bright rub mark.
For high-value appearance parts, an intermediate inspection before packing catches the handling damage that final inspection at the customer would otherwise attribute to the supplier.
| Single part | Protective film, anti-static bag, foam |
|---|---|
| Batch of small parts | Tray with compartments, or bag per part |
| Large housing | Corner protectors, molded pulp, carton |
| Sea freight | VCI protection plus desiccant, wooden case |
Industry questions
Yes. Send a physical sample or a Pantone reference, and the first batch is approved against it. Two loads of the same alloy can still differ, so a colour-critical order is planned as one run.
Around 0.8–1 mm in aluminium on a supported section, and thicker where the part is unsupported or anodized. Below that the anodize growth and handling risk dominate.
Yes, laser engraving after anodizing for contrast, or before for a filled effect. Send vector artwork and the required depth and position.
Yes, and it is often the right call for small quantities or complex fin layouts. Above a few thousand pieces an extrusion usually wins on cost, with machining only on the base and mounting features.
Send the housing with the cosmetic faces marked.
Tell us which surfaces are visible and which finish is required, and the quote will separate cosmetic from functional processing instead of pricing everything as a show part.
From the shop notes
Longer answers to the questions these pages raise.