Clarity you can measure

For optical and diagnostic parts, “looks clear” is not a specification. We finish to measurable targets — roughness, flatness and transmission — and report the numbers with the shipment.

Capability 04 — Polishing & Surface Finishing

From machining marks to optical surfaces

Polishing is a controlled material-removal process, not cosmetic buffing. Over-polish changes geometry; under-polish leaves scatter sources. We qualify the route per part family and measure the result.

Flame & vapor polishing to restore transparency after machining without rounding critical edges.
Optical lapping for flatness below 2 µm over 50 mm and Ra ≤ 0.02 µm.
Annealing to relieve machining stress and eliminate later solvent-crack failures.
Functional coatings light-blocking, anti-scratch and anti-reflection options applied where the application needs them.

Discuss your part

Process route

How we run it, step by step

Surface assessment. Machined surfaces measured for roughness and waviness to select the polishing route.
Pre-lapping. Geometry-critical faces brought flat before any thermal polishing.
Polishing. Flame, vapor or lapping route per material and geometry, parameters logged.
Stress relief. Annealing cycle set per thickness to prevent delayed crazing.
Measurement & report. Ra, flatness and transmission measured; values included in the lot documentation.

Specifications

Process envelope

Typical values. Tighter limits are available after a drawing review — share the functional requirement rather than a blanket tolerance.

Parameter	Standard	Precision / achievable	Notes
Surface roughness	Ra 0.4 µm	Ra 0.02 µm	Optical lapping or diamond fly-cutting
Flatness after finishing	20 µm / 100 mm	2 µm / 50 mm	On lapped optical faces
Transmission (PMMA, 3 mm)	92% typical	on request	Measured per agreed wavelength range
Edge clarity (laser or polished)	visual acceptance	photometric	Defined per drawing on request
Coating options	light-blocking, anti-scratch	AR on request	Adhesion tested per lot
Annealing	standard for bonded parts	—	Cycle recorded in lot file

Applications

Where this process earns its keep

Lenses & light guides Machined and polished PMMA optics with documented transmission.
Diagnostic windows & cuvettes Low-scatter surfaces for absorbance and fluorescence measurements.
Display covers & panels Anti-scratch, anti-glare finishes with controlled haze.
Fluidic channel interiors Vapor-polished channels that reduce particulate adhesion.

$Polished acrylic lenses and light guides$

Send the drawing, get a process answer

Every RFQ is reviewed by a process engineer — expect a reply within one business day, with the route we would run and where cost can be removed.

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