Starrett-Webber Master Bars ensure vertical or horizontal measurement accuracies to +.000004, -0.000000 per inch or length, or +0.0001 mm, -0.0000 per 25 mm length.

These Standard Reference Bare are invaluable for use in checking table movement of machine tools, accuracy of vernier height gages, surface plate transfer measurement, and for final inspection of precision machine tools and coordinate measuring machines.

The improved "channel design" places additional measuring pads at appropriate points over the length of the bar as reference points for x, y, or z axis measurements. The alternating gage block jaws and spacer blocks are permanently wrung and fastened together to form 1" increments for English bars and 25 mm increments for metric bars.

A special bushing arrangement allows the master stack to conform to thermal conditions prevailing during use, thus providing a true master even under less than perfect laboratory conditions. Mating surfaces are treated during assembly to prevent corrosion.

Channel design permits use of the bar on its base (vertical) or on its back or either side (horizontal).

To order, contact [email protected], and specify RBC (English) or RBCM (Metric) followed by length.
Example: RBC25 = 25" English Bar. When ordering free-standing design, omit the "C".

Non-standard lengths and measuring increments are available on special order.

Certificate of Calibration is furnished with all bars (observational error ± 2 micro in./in. .05 micro m/25 mm). All models are furnished with storage case.