Before we start looking at the comparison between them, let’s highlight what a countersink and a counterbore are.
What is Countersink?
A countersink is a cone-shaped hole that is bored into a PCB. This hole creates room for a flat head screw or fastener to fit correctly once installed.
What is Counterbore?
A counterbore is more of a cylindrical flat-shaped hole. The hole formed has a flat bottom and allows a screw or fastener with a flat underside to fit. Also, the instrument that is used to create this feature is known as a counterbore. The word will be used interchangeably.
Differences and similarities of them
The practice of making a countersunk hole is known as countersinking. Now, a countersunk hole may come in different sizes of angles. It includes the standard sizes of 60, 82, and 90 degrees alongside the less popular 100, 110, and 120 degrees. However, the most frequently used degrees are 82, 90, and 100.
While the only angle applicable to a counterbore is a vertical zero degrees, it is just as effective as a countersink. It is important to note that when working with a wooden surface if you fail to countersink first but end up forcing the screw into this surface, not only will the wood’s stability and strength be compromised, but your work will consequently be an eyesore.
It is because the wood fibers will crack and become dented if not wholly damaged. It is much easier to counterbore a wooden surface; this is because counterboring does not require precision and accuracy in the angles. Also, in a counterbore, all the hole needs are a screw with a flat underside or one with a socket head that can fit with the surface or washer.
What are the applications of countersink and counterbore?
Usually, a printed circuit board is mounted via a screw in a hole. If you need a more evident fixture appearance and a safer installation, either a countersink or a counterbore hole can be used.
This drilling process is often done by hand through automated equipment. Drill a counterbore when using a grub screw; the hole creates a perfect foundation for the screw to overlap and fit perfectly into the hole.
What are they used for?
A countersunk hole in a PCB creates room for a clean installation and is ideal for tight-fitting applications in small devices. PCB countersink applications are found in mobile phones and another small wearable device.
A counterbore offers a cylindrical fit to the screw. It is flat bottomed and is cut to allow a socket cap screw to be used. This hexagon socket screw has a hex head and needs to be mounted safely on the PCB. It can be found in washers and other electronic devices that require tight and secure fittings.