This content requires Adobe Flash Player version
Either you do not have Adobe Flash Player installed,
or your version is too old,
or there is a problem with your Flash installation and we were unable to detect it.
OPTICAL POLYGONS Webber Optical Polygons provide an easy, accurate method of checking and calibrating angles. They are designed for use with autocollimators in measuring angle spacing.
The exclusive one-piece design provides compact, fixed master for precise angle spacing. Target faces are highly reflective and optically flat.
Chrome carbide polygons provide a hardness of Rockwell 71-73 C and a corrosion resistance 10-20 times that of 18-8 stainless steel, resulting in lifetime accuracy.
Maintenance problems are virtually eliminated due to their ruggedness and extreme stability.
A 1" mounting hole, flanged bushing, lapped washer and hold-down bolt, furnished with each unit, permit mounting the polygon in any desired attitude. Available in two accuracy grades. Furnished in case. Certificate of Calibration included.
To order polygons, specify number in the following key/sequence:
Optical Polygon OP No./Faces Decimal Accuracy Grade
Example: OP 3.0 = A 3-sided optical polygon with a 0 Reference Accuracy
Optical Polygon Specifications
No. of Sides 3 4 5 6 8 9
Angle Spacing Degrees 120 90 72 60 45 40 36 30
Optical Polygon Specifications Accuracy Grade
Reference: 0 Calibration: 1
Diameter Across Corners Inch (mm)
Height Inch (mm)
Inch (mm) Area Sq. In. Area Sq. Cm.
.75" x .75" (19 x 19mm)
Target Area Flatness* 4 µin.
* Excludes .020" (0.5mm) from edges. All sizes: Flatness and parallelism – top and bottom – .00005"; maximum pyramidal error ±15 seconds.