CNC Machining Optical Glass: Optical Glass (CTE 7.1 x 10^-6 /K, 350 nm – 2.0 um); CNC Machining to +/-0.01 mm positional. Single-piece prototypes to production volumes, quoted from your drawing.
cnc machining optical glass is a materials problem before it is a machining problem. Optical Glass has certified refractive index and dispersion and a Knoop hardness of 610 kg/mm2, so the cnc machining recipe – feeds, coolant, tooling – differs from what works on ordinary float glass. The line runs 4-axis machining centers with diamond tooling and through-spindle coolant and holds +/-0.01 mm positional.
Key parameters
| Material | Optical Glass (N-BK7, H-K9L and filter glass sets) |
|---|---|
| Thermal expansion (CTE) | 7.1 x 10^-6 /K |
| Service temperature | 400 C (Tg 557 C) |
| Transmission range | 350 nm – 2.0 um |
| Density | 2.51 g/cm3 |
| Knoop hardness | 610 kg/mm2 |
| Refractive index | 1.5168 @ 587 nm |
| Stock thickness | 0.30 – 50 mm |
| Maximum blank size | 300 mm diameter |
| Process | CNC Machining |
| Working tolerance | +/-0.01 mm positional |
| Minimum feature | 0.4 mm slot width |
| Surface finish | Ra 0.4 um ground, optional polish |
| Thickness window | 0.5 – 50 mm |
| Edge condition | chamfered 0.1 – 0.5 mm as standard |
| RFQ inputs | PDF/DXF/STEP drawing, quantity brackets, surface and edge spec |
Design guidance
Three items decide most of the cost and lead time on this work:
- Material note: index-certified blanks must be oriented and serialized through the shop to keep melt traceability.
- Process boundary: internal corners carry a minimum radius equal to the smallest practical tool, typically R0.5 mm.
- Over-specification is the quiet budget killer: a 20/10 scratch-dig face costs roughly three times an 80/50 face, so grade each surface individually.
The full rules live in our tolerance design guide and holes and edges design guide.
Manufacturing capability
The core strength of CNC Machining is complex 3D geometry – pockets, steps, counterbores and compound edges in one setup. The honest limit: internal corners carry a minimum radius equal to the smallest practical tool, typically R0.5 mm. Both belong on the drawing before quoting, not after.
One material, many routes: on Optical Glass we also quote edge grinding, laser cutting, polishing, ultrasonic machining, and multi-step drawings are the norm rather than the exception.
Application context
cnc machining optical glass shows up across ccd inspection equipment (CCD cover plates, reference grids, stage glass); scientific instruments (reference flats, cells, prism mounts, stage inserts); optical sensors (sensor windows, filter caps, lens covers). Background reading on the underlying material science: RP Photonics: optical glass.
Dimensions still moving? Configure this part live in the 3D + 2D builder below, or open the full custom glass machining 3D + 2D builder to start from a blank canvas.
For adjacent specifications, see precision glass grinding, CNC machining capability, thickness and flatness guide.
Buyer questions, answered
What equipment runs the cnc machining work?
4-axis machining centers with diamond tooling and through-spindle coolant.
Is there a minimum order for cnc machining optical glass?
No. Single prototypes are accepted, and pricing steps down at 10, 100 and 1,000 pieces.
How fast can prototypes ship?
Machined prototypes ship in 5 – 10 working days. Coated or bonded parts add 1 – 2 weeks depending on queue slots.
What files do you need for a quote?
A dimensioned PDF plus DXF or STEP geometry. If only a sketch exists, our drawing review service formalizes it before quoting.
Do parts ship with inspection data?
Dimensional reports, surface certificates and material certs per melt are available; specify the level on the RFQ.
Specifications on this page were last reviewed by our engineering team in August 2026.