Straight Edge Flatness Tolerance 0.018 mm Calibration Certificate Not Certified Straightness Tolerance Not Applicable Parallelism Tolerance 27 micron Thickness Not Applicable Coating Not Applicable Flexibility Rigid Edge Style Square Color Green Backing Material Not Applicable Finish Not Applicable System of Measurement Metric/SAE Includes Case Length - SAE 80 in Length - Metric 2 000 mm Width - SAE 1 9/16 in Width - Metric 40 mm Magnetic Nonmagnetic Material Magnalium