Automotion Components is a leading manufacturer of captive screws (also known as captive nut fasteners) and captive thumb screws. Also available to purchase online are threaded washers and retaining flanges for captive screw installation on thin or non-threaded panels. We manufacture our captive screws in many materials, including stainless steel (e.g. for medical applications), titanium (for aerospace etc.), and many others!
Captive screws are an important industrial component providing permanent fastenings – they do not fall out of equipment even when loosened. For safety reasons, permanent fastening is required on certain equipment, such as safety covers/panels, to comply with EU law (2006/42/EC; Machine Safety Directive) and/or ISO 14120. We produce precision-made captive screws at our UK factory and hold large quantities of stock, meaning we can usually ship to you on the same day you place an order. We can also manufacture bespoke captive screw dimensions to customer technical drawings or designs with short lead times. We have a thorough quality process (ISO 9001:2015 certified) and our materials are fully traceable. Certificates of compliance available on request.
Captive screws are designed to provide “captivation” (meaning a permanent hold). In the past, screws were going missing during machine maintenance, leading to guard panels being improperly reattached after servicing, resutling in workplace injuries when people accidentally put their hands inside machinery. The use of captive screws minimises the chances of a screw being lost during servicing or maintenance because the captive screw is more likely to remain with an assembly - e.g. a guard panel, that can be lifted off another part.
In general, captive screws have a smooth non-threaded shoulder that has a smaller diameter than the threaded portion at the end. When fixing in place, the screw is screwed firstly through the panel (or cover) and then finally into the second part of the structure (e.g. a housing for machinery). This means that when you unscrew a captive screw, it comes away from the housing but the smooth shoulder remains within the cover panel. Therefore, the captive screw remains attached to the cover panel unless specifically removed by means of the panel's threaded hole (or washer/retaining flange). This is advantageous because the risk of losing a component is minimised and the panel can be re-mounted easily and quickly. In addition, if the equipment is subject to vibration or other disturbances, even though the screw could come loose, it will not fall out and cause damage to a production line, for example.
For installation diagrams, videos, and more information about how captive screws work, please visit our captive screws technical page.
...in stainless steel (AISI 303 (A2) and 316 (A4) series), titanium, aluminium and more. Metric and imperial dimensions. See our technical information page to read more about the materials and finishes we can produce.
These captive screws can be hand-tightened and are excellent options for panels that need to be removed often for servicing. Standard sizes M3 - M6 and lengths 8 - 30mm. Available in titanium and stainless steel (AISI 303 and 316 series), and with blackened finish. Other materials and finishes on request.
Special thin diameter slotted head captive thumb screws in stainless steel (AISI 303 or 316 series) and titanium. Pointed end for easy screw end location. Thread sizes M3 - M6 and lengths 10 - 50mm. Also available on request in steel (anodised, black oxide or zinc plated), brass, aluminium etc.
Please note that you can find more detailed information about our range of materials and finishes on our captive screws technical page.
Cheese head captive screw with hex drive. Many other head types available on request.
Cap head captive screw in steel, with blackened finish. Other finishes, such as zinc-plating, are available on request.
Our extensive range of captive screws is also available in titanium (grades 2 and 5 - ideal for lightweight/aerospace applications), steel, brass, aluminium etc. Please get in touch to discuss your requirements.
This product is available in stock in many variations - this example is a cap head TX (hexalobular/star) drive in AISI 316 series stainless steel (very corrosion resistant marine grade) with blackened finish. We can also passivate 316 series stainless steel for added resistance to corrosion.
Some panels are that require captive screw fastening cannot be threaded, or are too thin for threading. Some of our customers prefer to use a non-threaded panel with a threaded captive washer (e.g. P0168) or retainer flange/mounting flange (for thin panels; e.g. P0169).
To understand more about how retaining flanges for captive screws work, including an instruction video, please see our captive screws technical information page.
Our captive screws come in a range of head styles, materials and finishes. Our most popular captive screws are made from stainless steel (AISI 303, 1.4305) or marine-grade stainless steel (AISI 316, 1.4401). The strength class of the stainless steels used to produce our captive screws is class 50. We also have titanium (ASTM B348 grades 2 and 5) captive screws in stock and many more options for bespoke products.
We can manufacture any special requirements to customer drawings easily on our fully automated machines (we may require a minimum batch size for this bespoke option). Other material choices include steel, titanium, monel, aluminium etc. Finishing options include a black oxide coating, zinc plating and more. We can also make a variety of special head types. See our captive screws technical information page for more details.
Our extensive range of captive screws is precision made and finished to the highest standards. We manufacture our products in the south of England and export them all over the world. We hold large volumes of captive screws in stock and can usually offer extremely quick turnaround times with same-day shipping as standard once an order is placed. Full export documentation is always provided for overseas customers. Our friendly customer service team is on hand to help you find the product which will make your designs come to life!
As specialists in linear motion systems we offer an array of linear rails to suit any application. So whether you need lightweight aluminium rails for use in aviation applications or stainless steel rails for when exposure to water or corrosive chemicals is a factor, our knowledgeable technical engineers are always on hand to provide assistance.
Delve into our Linear Motion Catalogue and explore the full range of products we can offer - available to download as a PDF or request a print copy for free.