HLS-11SS HEICO Fastening Systems HEICO-LOCK Washers , Manufacturer Part#: HLS-11SS , Manufacturer: HEICO Fastening Systems , Brand: HEICO-LOCK Washers , UOM (Inch or Metric): Metric , Material: Stainless Steel , Finish: AISI 316L , Bolt Size: 7/16 Inch UNC (M11) , Inside Diameter: 0.450 Inch (11.40mm) , Outside Diameter: 0.730 Inch (18.50mm)