A captive washer is a type of retaining washer commonly used to securely fasten screws within an assembly, affording a permanent hold.

Check out this video of the captive washer installation process.
Unlike a conventional washer, which is designed to aid in fastening a bolted component or a screw to a female threaded part, the captive washer acts as a retainer to ensure there is no risk of parts dropping free, causing foreign object contamination or fastener loss.
What makes Accu’s captive washers unique?
Accu supplies a wide range of precision engineering components to over 50% of the world’s top 100 manufacturers.
Accu’s captive washers are designed to be as easy to install as standard threaded washers, but with the permanence of a push-on retaining washer. This simplifies assembly by a thread-on construction. But unlike push-on washers, they can even be installed upside down with no loss of function.
These captive washers are manufactured to a new UK/ EU registered design, with clear advantages over the standard push-on style, or flat threaded disc.
How to install?
A captive screw or bolt is inserted through a clearance hole in the panel, with the captive washer being screwed onto the end of the thread and over to the waisted shank, also commonly known as the captive shank. This action holds the screw or bolt in place temporarily, allowing for removal if required, while still retaining all parts to be fastened into one assembly.
When the panel is tightened into place, the washer deforms and becomes permanently attached to the screw. The captive washer retains the fasteners in the panel, ensuring that they cannot fall out when the panel is removed from the assembly.
Accu’s captive washers are suitable for use with a range of different types of captive screws, offering a versatile retaining solution, depending on the preferred head or drive type.
Learn more here.
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Filed Under: Fastening + joining, Washers • spacers