Here at BS Fixings, we offer an extensive range of screws, to be used with a vast range of materials including wood, plasterboard, plastics, and even metal. As a company that specialises in fixings and fastenings, we know a lot about the many variations of screws, but do you?

 One key feature of a screw is the thread (the helical grooves that are found along the shaft/shank of the screw) which enables the screw to become secured in the surface it is being driven into. There are two main types of threads, full thread and partial thread, which we are going cover in this blog post.

What are full-threaded screws?

A fully threaded screw has grooves running all the way from the head of the screw to the tip. These types of screws are best used for grip strength, as the full thread allows the pressure to spread along the whole of the shaft, with the largest holding strength at the head of the screw. Fully threaded screws tend to have a self-tapping tip, so they can be drilled straight into the material, preventing surfaces such as wood from splitting. As the grooves travel along the entire shaft, fully threaded screws are less likely to become loose over time.

Full threaded screws are commonly used in the automotive industry, retrofit, and new build projects, as well as general wood construction tasks.

full threaded screw

An example of a full-threaded screw that we stock on our website is the A2 Stainless Steel Pozidrive Wood Screw. Manufactured out of top-quality 304 stainless steel for corrosion resistance, these screws are designed to secure softwoods, hardwood, chipboard, and MDF. This screw also has a double countersunk head, which allows for a flush, smooth finish, and a secure fastening. Countersunk heads are particularly useful for wood-to-wood and also steel-to-wood fastenings.

What are partial thread screws?

As you might’ve guessed, partial screws only have threads running halfway up the shaft. The top end of the screw, near the head, has a smooth section which is completely free from any helical grooves. This part of the screw is commonly known as the shoulder of the screw and is designed to add strength and resistance. The unthreaded section pulls materials such as wood and plywood tightly together, for example in panel-to-beam projects.

When choosing a partial thread screw, it is important to consider the length of the non-threaded part, as you will want it to correspond to the thickness of the material that you are securing, so it does not split or bulge. The bottom section of the screw, where the threads are, will fix the lower piece of wood in place, whilst the upper piece will be held tightly in place by the screw head and smooth part of the shaft.

partial thread screw

The SPAX T-STAR Plus Flat CSK MDF Wirox Coated Screws are a type of partially threaded screw, which are especially useful for MDF and particle boards. They are manufactured with a smaller 75-degree head, which allows for a clean finish. Similar to the fully threaded screws mentioned above, these screws are self-drilling, which offers an easy and simple installation. For extra corrosion protection, the screws are coated in Chromium VI, and therefore can be used for a range of purposes.

On our website, we have an entire catalogue of stainless steel screws, containing a range of full and partially threaded screws. If you are currently looking for some high-quality screws, we recommend having a browse at our product selection. If you have any further questions about the types of screws we stock or any of our other products, please feel free to contact us today and we will be more than happy to help!