Quality Requirements for Mirror & Coating

Description Items

Quality Requirements

Mirror Quality(MQ)

Select Quality(SQ)

Thickness

Tolerance

Nominal Thickness

Tolerance

Tolerance

2.0

1.80-2.20

1.80-2.20

3.0

2.70-3.00

2.70-3.00

4.0

3.80-4.20

3.80-4.20

5.0

4.70-5.00

4.70-5.00

6.0

5.80-6.20

5.80-6.20

8.0

-------------

7.70-8.30

10.0

-------------

9.70-10.30

12.0

-------------

11.70-12.30

Size Tolerance

Nominal Thickness

STOCK INVENTORY SHEETS CUT SIZE

2.0-6.0

± 3mm

± 2mm

8.0-12.0

± 6mm

± 3mm

Bow & Dish

2.0-3.0

≤1.5mm/m

4.0-12.0

≤1.5mm/m

Edge Quality

Flake

≤4mm

≤4mm

Bevel/Flare

≤3mm

≤3mm

Corner On/Off

≤4mm

≤4mm

Over Score & Cutter Drag

None allowed

None allowed

Squareness

For all thicknesses

Diagonal measurement differece/2 ≤0.2% of the diagonal length

Optical

Distortion

2.0-3.0mm

Zebra Reading ≥50 °

4.0-12.0mm

Zebra Reading ≥55°

Surface Flaws

Linear

Flaws

When viewed under a normal fluorescent inspection light source

Not visible viewed at 0.5 meters

Not visible viewed at 1.0 meter

Spot Marks

Same as for linear flaws

Same as for point defects

Point

Defects

Defect Size(d)

Number of Defects allowed Per Square Meter of Glass

d ≤0.5mm

Allowed

Allowed

0.5<d ≤1.0

0.3

Allowed

1.0<d ≤1.5

0.1

0.2

d>1.5

None

None