Retaining Washers, also known as Captive Washers, are specifically designed to be used alongside Captive Screws to create a self-retaining fastening which locks in place after installation.
Captive Fastening Solution
Captive Fasteners are designed to aid compliance with EU Machine Safety Directive 2006/42/EC and EU regulations on equipment such as safety guards. They work by preventing screws from being fully removed, either intentionally or by accident, from housing assemblies, such as panels on machinery.
The curved flaps on the inside of the Captive Washer are designed to flatten around the unthreaded shank of a Captive Screw, thereby reducing the retaining washer's internal diameter and thus preventing it from passing back over the threaded portion of the screw or bolt.
Captive Washer Materials
Accu's Washers for Captive Screws are designed for use with our Stainless Steel Captive Screw range. This type of retaining washer is made from Austempered Carbon Steel - with either a Bright Zinc Plated (BZP Carbon Steel) or Phosphate and Oil (Black Carbon Steel) finish.
Accu's Plastic Retaining Washers are a lightweight and cost-effective alternative, available in HDPE, Nylon and PA (Polyamide).