The SEM or combi screw is the simple idea of combining a screw with one or more free spinning captive washers into one unit…

Not only do SEMs fasteners reduce part count and wastage -no more lost washers that have slipped out of hand and rolled into a dark place never to be seen again!  SEMs also benefit the user with time saved on applications when using them. With the operator only needing to fasten exactly what they need to, without having to fumble with one or a collection of washers onto a thread whilst applying tightening torque, the simplicity of having the washers attached to an all-in-one encapsulated unit simplifies the task to speed up production and minimise errors in application.

There are many varients of the SEMS screw and with our extensive range we are one of Europes largest stockists.  Below you will find more information relating to this type of fastener. Call our friendly service at 01494 462 322, or email This email address is being protected from spambots. You need JavaScript enabled to view it. if you have any queries.

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Pre-assembled SEMS screws, sometimes known as combi screws, combine a screw with one or more free spinning captive washers. With our large stock and our extended ranges, there are literally hundreds of SEMS screw combinations to choose from, including:

• Thread Types – Machine Screw; Self Tapping; Thread Cutting; Thread Forming; HI LO
• Drive Types – Pozi; Phillips; Slotted; Combi; 6 Lobe; Hex; Other
• Washer Types – Flat; Spring; Square; Conical; Internal Tooth; External; Single or Double
• Head Types – Hexagon; Pan; Socket Cap/Button; Round; Cheese

With such an extensive range, we are able to create almost any type of washer and screw combination, enabling us to provide a bespoke solution for your business’s specific fastening requirements. However, we also stock some of the most popular SEMS screw combinations, including external shake proof, internal shake proof, and every configuration of flat and spring washers.

Why Choose Staytite

The benefits of choosing Staytite include:

• An extensive range of cost effective fastening solutions suitable for various industrial, domestic, and bespoke applications.
• A commitment to providing the highest possible standards of services and products, with all of our practices abiding to a stringent ISO 9001:2015 accredited Quality Management System.
• A dedicated team of specialists, all of whom are ready to provide expert technical support at a moment’s notice.
• An exceptional wealth of knowledge, which we have been using to meet our customers’ production needs since 1978.

At Staytite, we’ve been providing a wide variety industries with a complete fastening solution service, since 1978, routinely working with businesses and OEMs in the aerospace, automotive, marine, IT, and telecommunications sectors.

View our catalogue to see our complete range of SEMS screws. We understand that the choice can be overwhelming, so if you are unsure which SEMS screw combination is best suited to your requirements, please do not hesitate to get in touch, and we will be happy to advise. 

To request a quote, or some free samples of our SEMS screws, call 01494 462 322, or email This email address is being protected from spambots. You need JavaScript enabled to view it.