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 |
Getting the drawing right
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.
What the process holds
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 sandblasting, dicing, cnc machining, laser cutting in our shop – most real parts combine two or three of these steps.
Who orders this
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 builder below, draw a dimensioned 2D drawing from it, or open the site-wide custom glass machining 3D + 2D builder for fully custom parts.
Engineers scoping this work usually also review ultra-thin glass materials, AR coated glass materials, edge grinding overview.
Buyer questions, answered
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.
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.
Specifications on this page were last reviewed by our engineering team in August 2026.