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Prisms India Private Limited

Phone : +91-413-2277059

Mobile : +91-9843044707

Prisms India Private Limited

Optical Parallels

We are the only manufacturer & suppliers of Optical Parallels in india. Optical Parallels are used for checking Flatness and Parallelism of Micrometer measuring faces. These are supplied as a set of four numbers with thickness increment of 0.125 mm (one fourth of the pitch of the Micrometer). Optical Parallels are made from Fused Silica/Fused Quartz material as the material has environmental durability, and a low coefficient of thermal / Linear expansion and as well resistant to abrasion.

The parallels are manufactured to comply with the NPL (National Physical Laboratory) specification MOY/SCMI/54

  • Accompanied by Flatness Inspection Report
  • Inspection in Laser Fizeau Interferometer
  • Reference Flat (»/20) traceable to NIST.
  • Evaluation of Flatness with Licensed Quick Fringe Software
  • Cosmetic Defects : According to US MIL Std
  • Supplied in Wooden Box


Material BK-7 / Fused Silica (Suffix A), Fused Quartz
Dimensional Tolerance ± 0.15 mm
Thickness Tolerance ± 0.01 mm
Surface Quality 80-50 Scratch & Dig
Surface Accuracy 0.2 microns
Parallelism 0.1 microns
Parallelism Bevel 0.5 mm x 45°
Diameter 30 mm +/- 0.15 mm
Flatness 0.1 microns


Part No Diameter Thickness (mm)
OP-01 / OP-01A 30 mm 12.000, 12.127, 12.250, 12.375
OP-02 / OP-02A 50 mm 25.000, 25.127, 25.250, 25.375