Lapping Soda-Lime Glass: Soda-Lime Glass (CTE 9.0 x 10^-6 /K, 360 nm – 2.0 um); Lapping to flatness 1 – 3 um. Single-piece prototypes to production volumes, quoted from your drawing.
The combination of Soda-Lime Glass and Lapping comes up constantly in RFQs for a reason – the material offers temperable for 4-5x strength, and Lapping is the right way to get accurate geometry into it. Expect flatness 1 – 3 um and Ra 0.2 – 0.6 um matte.
The numbers
| Material | Soda-Lime Glass (Float per ASTM C1036, low-iron option) |
|---|---|
| Thermal expansion (CTE) | 9.0 x 10^-6 /K |
| Service temperature | 350 C continuous |
| Transmission range | 360 nm – 2.0 um |
| Density | 2.50 g/cm3 |
| Knoop hardness | 585 kg/mm2 |
| Refractive index | 1.52 @ 587 nm |
| Stock thickness | 0.40 – 19 mm |
| Maximum blank size | 1,000 x 800 mm |
| Process | Lapping |
| Working tolerance | flatness 1 – 3 um |
| Minimum feature | thickness +/-0.003 mm |
| Surface finish | Ra 0.2 – 0.6 um matte |
| Thickness window | 0.2 – 40 mm |
| Edge condition | not applicable |
| RFQ inputs | PDF/DXF/STEP drawing, quantity brackets, surface and edge spec |
Specification advice
The shop-floor rules that matter here:
- Material note: higher CTE means edge chips propagate under thermal load, so edge finishing quality drives reliability.
- Process boundary: lapped faces are translucent-matte; optical clarity requires a subsequent polish.
- 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.
For the complete framework, see the tolerance design guide and the holes and edges design guide.
Process window
Lapping earns its place through restoring flatness and parallelism on plates and repairing bowed stock. Its boundary condition – lapped faces are translucent-matte; optical clarity requires a subsequent polish – is the first thing our DFM review checks.
Beyond this page, Soda-Lime Glass routinely runs through grinding, edge grinding, cnc machining in our shop – most real parts combine two or three of these steps.
Where these parts end up
Orders for lapping soda-lime glass cluster in led packaging (groove covers, phosphor carriers, package windows); industrial displays (touch covers, gauge windows, printed bezels). Background reading on the underlying material science: ASTM C1036 flat glass standard.
The fastest route to a quote is geometry: use the 3D builder below, draw a dimensioned 2D drawing from it, or open the site-wide custom glass machining 3D + 2D builder for fully custom parts.
Related reading on this site: glass wafer bonding, ITO coated glass, material selection guide.
Buyer questions, answered
What equipment runs the lapping work?
Cast-iron lap plates with boron carbide and alumina slurries.
Is there a minimum order for lapping soda-lime 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.
Specifications on this page were last reviewed by our engineering team in September 2026.