Flat Washer Flat Washer Type Standard Dimensional Standards DIN 9021 Material Stainless Steel Material Grade/Class 316 Finish Plain For Screw Size M4 Inside Diameter 4.3 mm Outside Diameter 12 mm Maximum Thickness 1 mm System of Measurement Metric Minimum Thickness 1 mm Maximum Temperature 302 Degrees F Minimum Temperature -58 Degrees F Pack Size Small Pack Package Quantity 50