When shopping for screws, you may encounter socket cap screws. They feature a head and a threaded shank. But the head of a socket cap screw features a different drive type than that of other screws.
Socket Cap Screws Explained
Socket cap screws are threaded fasteners with a hexagonal recess for the drive type. The drive type refers to the way in which a threaded fastener is driven into an object. Most screws, including socket cap screws, have a recess in their head. This recess determines the drive type. Socket cap screws have a hexagonal recess.
The photo above depicts a set of socket cap screws. While they look like most other screws, they don’t feature the same recess. Other screws may have a Philips or flat-head recess. But socket cap screws have a hexagonal recess consisting of six sides.
Common features of socket cap screws include the following:
- Fully threaded shank
- Cylinder head
- Hexagonal recess in the head
- Heavy-duty construction
- Available in stainless steel and alloy materials
- Requires less clearance to tighten than other types of screws
How to Install Socket Cap Screws
Installing, as well as removing, socket cap screws requires the use of an Allen wrench. Also known as a hex key, it’s a piece of metal consisting of two arms: a long arm and a short arm. Allen wrenches are made of steel, and they are formed to achieve a hexagonal shape.
With their hexagonal shape, you can use an Allen wrench to install socket cap screws. After positioning a socket cap screw over a threaded hole, insert the Allen wrench in the screw’s hexagonal recess. Turning the Allen wrench clockwise will then tighten the socket cap screw. You can loosen or remove the socket cap screw by turning the Allen wrench counterclockwise.
Button vs Flat Socket Cap Screws
There are many different types of socket cap screws, such as button and flat. Button and flat socket cap screws both feature a hexagonal recess, but they have different head types.
Button socket cap screws have a mushroom-shaped head. Within the head is the same hexagonal recess as other socket cap screws. Button socket cap screws simply have a protruding head that’s shaped like a mushroom or button.
Flat socket cap screws have a flat head. The top of the head is completely flat. This allows for a flush finish when installed.