up for sale is a Optical Flat Parallel set PM-15 Metrology Planglas

a few very small tiny scratches on  flats otherwise excellent  condition

Technical characteristics of PM-15 plates:
 PM-15 Plate diameter, mm 30±1
Plate heights, mm 15.50 15.62 15.75 15.87
Limit of measurements, mm 0-25
The deviation from the mutual parallelism of the measuring planes does not exceed, μm 0.6
Deviation from the flatness of the measuring planes does not exceed, µm ±0.1
Local deviation from flatness, no more than, µm ±0.03


PM-15 type glass sliders are designed to check the flatness and mutual parallelism of the surfaces of micrometers and staples by the interference method. Plane-parallel glass plates have the form of round straight cylinders with polished end surfaces, which are measuring. The cylindrical surface of the plates must be matte, except for the area intended for marking. The size of a plane-parallel glass plate for checking micrometers is determined by the shortest distance between its measuring planes. Plates come in 4 pieces per set. The material of the plates is glass grade K8 GOST 3514-76

Overall excellent condition

RARE FIND and excellent addition to your collection or project

please check my other listings for other similar items

please look at the photos,youll get exactly the item you are viewing

 the item ships worldwide via registered air mail(up to 25 business days to receive in some cases)

yes,the shipping can be combine(each next item -30% on its shipping)

any questions are welcomed

please pay attention to the shipping price(not negotiable)

GOOD LUCK AND HAPPY BIDDING