Machine Tolerances for Cover Glass Processing

In the cover glass industry, machine tolerance control is critical for precision processing. Below are the key tolerance ranges of common processing equipment, based on practical production experience.

1. CNC Edging Machines (General Precision)

Suitable for mid-range cover glass; tolerances: chamfer angle ±0.5°–±1.0°, chamfer width ±0.1mm–±0.2mm, edge thickness uniformity ±0.08mm, linear processing ±0.1mm per meter.

2. High-Precision CNC Edging Machines

For high-end consumer electronics; tolerances: chamfer angle ±0.1°–±0.3°, chamfer width ±0.03mm–±0.05mm, edge thickness uniformity ±0.02mm, linear processing ±0.05mm per meter.

3. Multi-Axis CNC Edging Machines

For complex chamfers (step edges, irregular 2.5D); tolerances: arc radius ±0.02mm–±0.04mm, step height/width ±0.03mm, irregular edge angle ±0.2°, multi-chamfer positional tolerance ±0.05mm (weekly calibration required).

4. Polishing Machines

General type (seamed/flat edges): surface flatness ±0.05mm; high-precision type (beveled/2.5D edges): surface flatness ±0.01mm–±0.02mm, gloss uniformity ≤5%, polishing wheel runout ±0.01mm.

5. Ultrasonic Cleaning Machines

Tolerances: surface particle residue <5μm, no visible water spots after drying, surface cleanliness ≥99.5% (tested by particle counter).

6. Coordinate Measuring Machines (CMM)

Inspection tolerances: chamfer angle ±0.05°, chamfer width/radius ±0.01mm, edge thickness ±0.005mm (monthly calibration required).

Practically, match machine tolerances to product needs; regular maintenance and calibration prevent tolerance drift.