Biconvex lens Ø 31.5 mm 18 dioptres - pack of 10 made of optical glass, ground and polished

Size: Ø 31.5 mm
Optical power: 18 dioptres
Focal length: 56 mm
Rim thickness: 1.2+/-0.2 mm
centre thickness: 5.6+/-0.2 mm
Cylindrical rim: 1 - 2.5 mm (pressed edge)

Tolerances:
from 40 mm Ø the size tolerances are subject to the deviations from the nominal dimension that the raw glass compacts have.

These are:
for 40 - 75 mm Ø -0.3 mm
for 75 - 120 mm Ø -0.5 mm
over 120 mm Ø -0.8 - 0.9 mm