Some mounting hardware is required for PCBs, and most of the PCB fabrications include non-plated mounting holes. The two common types of PCB holes are counterbore and countersink holes. The drilling method is typically the way of drilling out larger diameters for the opening's highest few millimeters. Countersinking and counterbore are both used for drilling holes. To select the one suitable is quite challenging, but understanding the difference between them will be helpful.
Countersinking the process of cutting a conical hole into cloth to permit a fastener sort of a screw to be driven into the fabric deep enough for its head to be flush with (or below) the material's surface. It also allows the screw head's conical bottom to suit the fabric perfectly.
The hole created through this process is named a countersink. It's defined by a spread of measures, including its major hole diameter, primary hole diameter, depth, and angle. All of these will vary, counting on the sort of screw getting used.
The tools used for creating such holes are often mentioned as "countersinks" also. Besides getting used extensively in woodworking, they're commonly utilized in manufacturing too.
Counterboring is the process of cutting a cylindrical hole into cloth to permit ahead of a fastener sort of a bolt to be flush with or below the material's surface. Frequently, Forstner bits are used to achieve this result.
The hole created through this process is named a counterbore. Its diameter and depth define it. The diameter of a counterbore is usually slightly larger than the fastener head's diameter. Just in case a washer is employed, it's somewhat more extensive than the diameter of that.
Like in the previous case, the tools used for creating counterbores are mentioned as, well, "counterbores."
A counterbore may be a circular hole, usually with sections at different diameters. It's drilled to permit a captive head or the other fixings with square shoulders to seamlessly sink into the drilled material. On the opposite hand, a countersunk hole may be a significant obtuse-angled relief or bevel drilled at the sting of a round hole and designed to permit for fixings with sunk heads, like rivets and screws. The opening allows for the highest of the fixings to sit flush with the fabric.
The counterbore holes are more square and broader, which allows for the addition of washers before fastening the fixings, while the countersink holes are conical, which matches the angled shape on the lower side of the flat-head screws.
Because of their different shapes, the two processes are used with different types of fasteners. Countersinking is employed with screws and other fasteners that have heads that are conical on rock bottom.
Counterboring is employed with fasteners that have heads that are flat on rock bottom. That has bolts and screws with hexagonal heads, rivets used with washers, ends of bolts with nuts and caps, and so on.
In either case, picking the proper process for the appropriate application allows the rock bottom of the fastener's head to take a seat perfectly flush with the fabric.
While whenever a screw with a conical bottom is driven into a bit of wood or other material should be countersunk for the most straightforward possible quality of the finished product, that's not always the case.
Especially so when it involves amateur woodworking.
The reason for that's that wood is soft enough for the screw to be "forced" to countersink itself. That said, countersinking is critical when working with PCBs, metal, and other materials that aren't as flexible as wood.
Counterboring, on the other hand, maybe a process that's harder to urge away without doing. That's because fasteners that need counterbores usually have much larger heads than standard screws. And, as such, they can't be "force-driven" like wood screws can.
Thus, counterboring is employed widely both in amateur woodworking applications and in additional professional settings – whether that be carpentry or manufacturing.