Why are optical mounts anodized black, and does the process affect precision?

Black Type II anodize kills stray reflections in the beam path. The layer grows roughly half into and half out of the surface — figure 5–12 µm per side — so precision bores and register faces are either masked or machined with the growth budgeted. A drawing that ignores this loses its fits at assembly.

What flatness can be held on optical breadboards and stage plates?

MIC-6 cast plate holds 0.05–0.1 mm/m machined conventionally, better with grinding as a final op. The reason MIC-6 over rolled plate is not the number on day one — it is that stress-relieved cast plate still measures the same after a season of thermal cycles.

When is Invar 36 worth its machining cost in an optical assembly?

When the thermal expansion budget is the design driver — laser cavities, interferometer frames, athermal lens cells. Invar cuts slowly and gums tooling, so a part costs several times its aluminum twin; if your temperature swing is small, 6061 with a compensated design is often the smarter spend.

Industry

Optics & Photonics

Name: CNC Machining for Optics & Photonics
Brand: FabVector

Micron-stable mounts and baseplates that hold an optical alignment for years.

FabVector machines Optics & Photonics parts in Aluminum 6061-T6, MIC-6 Cast Aluminum Plate, Invar 36, from 1 piece, with instant online estimates, engineer-reviewed quotes in 24 hours and NDA-protected files. Delivery with duties handled to the US, Canada, UK and Australia.

Materials: Aluminum 6061-T6, MIC-6 Cast Aluminum Plate, Invar 36
Minimum order: 1 piece
Estimate: ~60s online
Quote: engineer-reviewed 24h
IP: NDA from upload

What slows this industry down

Optical hardware fails invisibly: a mount that creeps a few microns or a baseplate that bows with the seasons puts a beam off target with no broken part to point at, so flatness, stability and stress-relieved machining matter more than any single tolerance. Thermal expansion drives material choice — MIC-6 for stability, Invar 36 where drift must approach zero — and few shops machine Invar well. Stray light makes matte black anodize an optical specification, not a cosmetic one. Vacuum and laser systems add cleanliness and low-outgassing demands, plus flatness and angle reports standard shops do not produce.

Typical parts we machine

Lens mounts and cells
Laser baseplates and optical benches
Filter wheels and aperture hardware
Precision kinematic adjusters and stages

Recommended materials

01Aluminum Alloys

Aluminum 6061-T6

The default CNC aluminum: strong enough for most jobs, machines fast, anodizes well.

02Aluminum Alloys

MIC-6 Cast Aluminum Plate

The flatness specialist: stress-relieved cast plate that will not move when you machine it.

03Specialty Metals

Invar 36

The dimensional anchor: ~1.2 ppm/K expansion for parts that must not move with temperature.

04Copper Alloys

Brass C360 (Free-Machining)

The machinability benchmark itself: fastest cycle times in the shop, naturally low-friction.

Recommended finishes

01Anodizing

Anodizing Type II (Dyed)

Color that cannot peel: dye locked inside the part’s own oxide layer.

02Mechanical Finishes

Bead Blasting

The uniform matte look: erases tool marks, hides fingerprints, preps perfect anodizing.

03Plating

Electroless Nickel Plating (ENP)

Plating without electricity: dead-uniform thickness everywhere, bores and threads included.

Certifications & standards

ISO 9001: We understand photonics buyers expect ISO 9001 process discipline plus flatness and angle inspection reports on critical optical interfaces.
RoHS / REACH: We support RoHS/REACH declarations for opto-mechanical assemblies entering instruments and laser products.

We understand and support these requirements; certification and documentation scope is confirmed per order.

Questions optics & photonics buyers ask

Why are optical mounts anodized black, and does the process affect precision?: Black Type II anodize kills stray reflections in the beam path. The layer grows roughly half into and half out of the surface — figure 5–12 µm per side — so precision bores and register faces are either masked or machined with the growth budgeted. A drawing that ignores this loses its fits at assembly.
What flatness can be held on optical breadboards and stage plates?: MIC-6 cast plate holds 0.05–0.1 mm/m machined conventionally, better with grinding as a final op. The reason MIC-6 over rolled plate is not the number on day one — it is that stress-relieved cast plate still measures the same after a season of thermal cycles.
When is Invar 36 worth its machining cost in an optical assembly?: When the thermal expansion budget is the design driver — laser cavities, interferometer frames, athermal lens cells. Invar cuts slowly and gums tooling, so a part costs several times its aluminum twin; if your temperature swing is small, 6061 with a compensated design is often the smarter spend.

Relevant services

CNC Milling

Machinist at the open door of a vertical machining center, tool holders staged in the foreground

3- and 4-axis vertical machining for housings, brackets, manifolds and structural parts.

Micro Machining

Micro-machined components beside a millimeter scale

High-speed spindles and Ø0.1 mm tooling for features below 1 mm and watch-scale parts.

5-Axis Machining

Five-axis machining of a complex impeller

Simultaneous 5-axis machining for impellers, freeform surfaces and compound-angle features.

Related engineering guides

Invar optical alignment stage CNC machining

Application Case: Invar Optical Alignment Stage CNC Machining

An optics and photonics RFQ playbook for Invar 36 alignment stages, low thermal expansion, datum control and inspection planning.

CNC machining service by country

Online CNC machining service USA Canada UK Australia

Have a part in mind?

Upload CAD or drawings. Eligible CNC work gets an instant estimate; other processes move to engineer review. NDA-protected from the first byte.

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