Captive Screws

Captive screws basically are specially designed to lock into position in a hole, enabling easy setting up and removing of the attached pieces even without the complete removal of the screw.

A conventional screw typically passes through a clearance hole in one part and then screws into a threaded hole in a second part — so the first part is clamped to the second.

However, when the fastener is unscrewed from the threaded hole in the second component, it can easily separate from the first one.

A captive screw is designed to prevent this from occurring. It can freely rotate within the first component, with some axial movement, but it’s unable to separate from it.

USES : Captive screws are used when fasteners must remain attached to equipment, such as in cover panels. They are a requirement for several machinery safety standards.

They provide a secure joining, and avoid fastener loss or damage that might be caused by a loose part.

Captive screws come with Philips, Allen head or standard heads that are designed for usage with drill equipment and ordinary screwdrivers.

Captive screws can be found in several configurations and sizes much like the conventional screws premeditated to be utilized for large number of applications.

Material: Stainless Steel AISI-304.
SS-316 on special order.
Size Range: M2 to M6 in ready stocks

Captive Screws Pan Phillips

Captive Pan Phillips Machine Screws SS-304 A2 B4K31 – Download Datasheet

Captive Pan Phillips Machine Screws SS-316 A4 B6K31 – Download Datasheet

Also available in unified series

Captive Pan Phillips Machine Screws UNC SS-304 A2 B4uK31 – Download Datasheet

Captive Screws Allen Cap

Captive Allen Cap Machine Screws SS-304 A2 B4K49 – Download Datasheet

Captive Allen Cap Machine Screws SS-316 A4 B6K49 – Download Datasheet

Installation of Captive Screws

Using a retaining washer

To install a captive screw on a panel using a retaining washer, the screw is first passed through a hole in the panel.
The washer is then screwed onto the captive screw, until the reduced diameter section is reached, retaining the screw on the panel.
Retaining Washers feature internal fins, which grip the thread of a fasteners, creating a self-retaining fastening. Retaining Washers are designed for use with Captive. The combination of Captive Screw and Retaining Washer creates a lightweight and cost-effective locking solution for safety applications.

A Plastic Retaining Washer is primarily used to hold screws and bolts in place during assembly and have a design that grips the outside of screw or bolt shank. Also known as an Anti Loss Washer, they provide insulation, cushioning and spacing. They help insulate fastening assemblies from moisture and electricity.

This washer range includes options with internal and external teeth with a tapered design. The washer slides/assembles on to the screw (or bolt) and is retained by the screw once assembled. The washer cold forms and fully enters the pitch of the screw to provide sealing.

These washers allow for preliminary mounting of the screw (or bolt) before securing with a nut. They are ideal when pre-assembly of the screw and washer is required.

These Washers have specially configured internal shape designed to grip the outside of the screw shank/threads.

Retaining Washer Plastic K8D19 – Download Datasheet

Using a retaining flange

To install a captive screw using a retaining flange, the flange is first pressed onto the panel. The captive screw is then screwed into the flange until the reduced diameter section is reached and the screw is retained.