HLS-16SS HEICO Fastening Systems HEICO-LOCK Washers , Manufacturer Part#: HLS-16SS , Manufacturer: HEICO Fastening Systems , Brand: HEICO-LOCK Washers , UOM (Inch or Metric): Metric , Material: Stainless Steel , Finish: AISI 316L , Bolt Size: 5/8 Inch UNC (M16) , Inside Diameter: 0.670 Inch (17.00mm) , Outside Diameter: 1.000 Inch (25.40mm)