Material Reference · Finish

Surface texture.
Visual character.
Each material differs.

Different materials yield different appearance after machining. Aluminum uniform silver, brass golden, stainless gray, plastics white/colored. Plan finish per material aesthetics.

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01 · Key principles

Key principles.

Aluminum machined

Silver-gray

Machined aluminum: even silver-gray surface. Good for anodize. Cosmetic Ra 0.4 µm achievable.

Brass machined

Golden yellow

Machined brass: golden yellow. Polish to mirror, or natural oxidize for darker.

Stainless machined

Gray, slightly blue

Machined stainless: gray with blue tint. Mirror polish reveals true tone.

Plastic machined

Material-dependent

Plastics show natural color. Acetal black/white, PEEK tan, polycarbonate clear, nylon ivory.

Steel machined

Gray-silver

Machined carbon steel: gray-silver. Quickly oxidizes — needs immediate finishing.

Copper machined

Salmon to red

Machined copper: bright salmon-red. Oxidizes to brown then green over time.

Titanium machined

Silver-gray

Machined titanium: similar to stainless. Anodize for color (no dye).

Magnesium machined

Light gray

Machined magnesium: light gray. Reactive — careful chip handling.

Bronze machined

Bronze-gold

Machined bronze: bronze-gold tone. Often left natural for aesthetic.

FAQ

Best material for cosmetic show parts?

Anodized aluminum for premium look. Mirror-polished stainless for industrial premium. Brushed brass for traditional aesthetic. Material choice affects entire aesthetic.

Anodize colors achievable?

Aluminum: black, red, blue, gold, green, custom dyes. Titanium: blue, purple, gold via interference colors. No anodize for stainless or steel.

Polishing achievable Ra?

Mirror polish Ra 0.05-0.1 µm. Standard polish Ra 0.4 µm. Brushed Ra 0.8-1.6 µm. Bead blast Ra 1.6-3.2 µm.

Aging and patina?

Brass develops patina (golden to dark). Copper greens (verdigris). Stainless stays stable. Aluminum oxidizes minimally if anodized.

Color matching across materials?

Standardize via post-process — paint or powder coat all parts same color. Or anodize aluminum + paint other materials.

Cosmetic vs functional finish?

Cosmetic typically Ra ≤ 0.4 µm. Functional Ra 1.6-3.2 µm typical. Tighten only when needed — Ra below 0.4 multiplies cost.