Flat Washer Flat Washer Type Standard Dimensional Standards ANSI B18.22.1 Material PEEK Material Grade/Class Grade 2 Finish Plain For Screw Size 1/2 in Inside Diameter 0.531 in Outside Diameter 1 1/16 in Maximum Thickness 0.095 in System of Measurement Inch Minimum Thickness 0.095 in Color Brown Maximum Temperature 500 Degrees F Minimum Temperature -50 Degrees F Pack Size Small Pack Rockwell Hardness D87.5 Thickness Tolerance +/-0.015 in Package Quantity 10