Socket Head Cap Screws (Bolts)

A socket head cap screw is a type of bolt with a hexagonal recess in its head.
It is also commonly referred to as a cap bolt or cap screw.
By inserting a hex key into the hexagonal socket and applying torque across all six sides, the screw can be tightened with high strength and is less likely to loosen.
Compared to using a screwdriver or spanner, it requires less working space, making it suitable for installation in confined areas.
They are widely used in various fields, including industrial equipment and machinery.

The main types include:
1. Socket Head Cap Screws
This is the most common type, featuring a cylindrical head. It is suitable for applications requiring high strength and high torque.

2. Socket Button Head Screws
With a low-profile, rounded head, they are ideal for panels and exterior parts where appearance is important.
In addition, the curved head surface helps suppress electric field concentration at the edges, making them less likely to cause discharge or leakage than cap screws in high-voltage equipment or environments with a risk of discharge
(such as vacuum equipment, electron beam equipment, and X-ray equipment).

3. Socket Flat Head Screws
The flat, countersunk head allows a flush finish with the fastening surface, making them ideal for locations where a protruding head must be avoided.

4. Socket Set Screws (Hollow Set Screws, Grub Screws)
These screws consist only of a threaded section without a head and are used to secure or position components by pressing the tip against a mating part.

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