Stainless Flat Washers 1/4 Inch, 304 Stainless Steel, 100 pieces (1/4 Flat Washer) by "Chenango Supply Co., Inc." 304 Series Stainless Steel, (18-8) Tensile - 100,000 psi to 125,000 psi, Hardness - 85 Rockwell B For 1/4 inch bolts and screws Great corrosion resistance for outside applications