Flat Washer Flat Washer Type Standard Dimensional Standards ANSI B18.22.1 Material PEEK Material Grade/Class Grade 2 Finish Plain For Screw Size #6 Inside Diameter 0.082 in Outside Diameter 3/8 in Maximum Thickness 0.266 in System of Measurement Inch Minimum Thickness 0.266 in Color Natural Maximum Temperature 500 Degrees F Minimum Temperature -50 Degrees F Pack Size Small Pack Resistance Properties Impact Resistant Radiation Resistant Wear Resistant Rockwell Hardness M103