Set Screws

Set screws also known as grub screws are a special type of screw used to secure moving or sliding parts securely into position. Set screws are completely threaded along the entire length and have no head. They are widely used in a range of sectors and industries. Here at Cromwell, we offer a wide selection of set screws from leading brands Qualfast, Bondhus and workshop.

Why set screws?

Set screws are considered a type of bolt, despite several key differences. They are designed to securely join and grip components together without the need for a nut. They do not have a head like standard screws and bolts, which allows them to sit flush and hidden within the workpiece with no protruding parts.

They are designed to be driven into an existing socket or holes, rather that driven into create a new hole. As a consequence, set screws typically show a better resistance to corrosion and weathering. Grub screw tend to be used in mechanical systems where there is not adequate space to fit protruding bolt heads or where multiple surfaces press or rub together. They allow machinery to function and move without restriction and allow a clean aesthetic.

Types of set screw

There are various types of set screw each different in appearance:
Conical point (cone point)  -   This is used when the thread part has insufficient thickness, and the lateral force is small.
Dog point  -   This type of set screw is used where the threaded part has sufficient thickness, and the lateral force is large.
Oval point  -   This style causes minimal surface damage to the held part and due to its shape allows for slight adjustments can be made without loosening the screw.
Cup point  -   This set screw is mainly used quick permanent and semi-permanent assemblies and when screw indentation by the screw point is acceptable.
Flat point  -   This is used when the lateral force is applied randomly and when threaded part has an insufficient thickness.
Knurled cup point  -   Similar to cup point but have a serrated point for added grip.


What is the difference between a set screw and a screw?
The main difference is set screws are fully threaded. This allows the entire length of the screw to be fully inserted into the object, unlike standard screw that have a screw head and tightened by a bolt.

Can I adjust a set screw?
Most set screws are designed to be used as a permanent fixing once seated into position. However, if you required a more adjustable set screw that can be slightly adjusted or loosened then the oval point is the most recommended.