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
Before sending the RFQ, check these against your drawing:
- 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 coring, polishing, drilling, laser cutting in our shop – most real parts combine two or three of these steps.
Where these parts end up
The recurring buyers of lapping soda-lime glass: 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 configurator below, or the site-wide custom glass machining 3D builder for fully custom parts.
Related reading on this site: machining tolerance guide, wafer dicing process, LED groove cover glass.
Buyer questions, answered
What tolerances are achievable on Soda-Lime Glass parts?
Ground features hold +/-0.01 mm and lapped thickness reaches +/-0.003 mm. Higher CTE means edge chips propagate under thermal load, so edge finishing quality drives reliability.
What thickness range do you stock for Soda-Lime Glass?
Standard stock spans 0.40 – 19 mm, with blanks up to 1,000 x 800 mm. Other formats are sourced per order.
How does Soda-Lime Glass behave under heat?
CTE is 9.0 x 10^-6 /K and continuous service reaches 350 C continuous, which is what drives its use where lowest cost per square meter matters.
What accuracy does lapping hold?
Flatness 1 – 3 um with minimum features of thickness +/-0.003 mm. Lapped faces are translucent-matte; optical clarity requires a subsequent polish.
Specifications on this page were last reviewed by our engineering team in July 2026.