What is countersink vs counterbore?
Counterboring and countersinking are the same things. But they have different definitions relative to where the hole is in relation to the inner shaft. Conical countersink bits have an angled profile, while a “counterbore” involves drilling straight down without a taper.
To countersink wood is a machining technique that produces a divot or conical shape hole. The purpose is to provide an area that will accept a flat head screw with the workpiece. Counterboring is a similar technique producing a larger hole than the lag screw. This is often necessary to fit a fastener with a non-standard profile, such as a carriage bolt head.
In most cases, this is done so nothing sticks out and provides a good finish.
Why countersink screws?
Countersinking screws keeps them flush with the material, preventing them from being damaged.
When hanging sheetrock, it’s essential to keep fasteners below the paper. If you don’t drive it deep enough, you’ll have a bump to deal with afterwards. An amateur mistake that kills productivity and makes your DIY project look bad.
To prevent harming your walls while mounting plasterboard, employ a specialist driver.
Countersunk screws sit flush when installed correctly and don’t pop through the paper. Drywall screws do a great job and are intended for the purpose – so there’s no need to worry about them standing proud.
Different Types of Countersink Drill
There are various countersink drill bits for wood and other applications. The most prevalent countersink angle in the USA is 82° and 90°, but others include 60°, 100°, 110°, and 120°. Because screws won’t sit properly in harder materials, the countersink angle is critical.
The most commonly found are the “combination countersink drill bit” and “Screwdriver Bit.” These two varieties can be found at most hardware stores. There are three types of countersinks: single flute, multi-fluted, and combination. The single flute or snail bit is designed for metal or plastic. It removes more waste fibres in a shorter period.
After drilling in any metals, a countersink tool’s “Deburring” feature is vital. This removes any burrs created, helping keep your work from being scratched.
Metal countersink bit
Only a 3 jaw chuck can accommodate a round shank countersink cutter. Hexagonal shanks are meant for electric screwdrivers. Depending on the model you’re searching for, they can be found for $19 and up.
HSS-CS DIN 335 countersink sets are ideal for counter sinking and deburring stainless steel. HSS-CB is a premium version for the same purpose.
Countersink bits for wood
There are a few different sorts when it comes to a countersink drill for wood. The most common type is the combo countersink drill bit sets. It’s how I do it most of the time because it’s easy to find and less likely to cause any damage to the board.
If you’re working in alloy or hardwood, you’ll want a countersink drill bit with a more precise inclination. The degree range isn’t as crucial while dealing with soft wood.
Another option is the combo drill bit set. This combo pack is a good option for wooden projects. It has wood plug cutters and countersinks, which might be difficult to find elsewhere.
Screwfix sells many brands of countersinks alongside their popular erbauer brand. With the average star rating for each product displayed near the item name.
How to Drill The Pilot Hole and Countersink a Screw Head
You need to know a few basic things before drilling pilot holes. The first is to measure the screw thread diameter. This helps you choose the correct twist bit for your clearance hole.
When you’ve selected the right wood drill bits, you can start! To begin, drill a screw hole in the piece of wood with the twist drill bit. Then, sink it below the wood surface with the countersink drill bit. Be careful not to overdo it, or it won’t look professional.
Drilling a Pilot Hole
Pilot holes are essential for driving wood screws. It’s hard to say how far down you should drill the countersink holes; it depends on the species. Installing fixtures in hardwood requires drilling down to 1/2 to 3/4 of the wood screw’s total length.
While this is unnecessary for softwood, concrete requires around 1/4 to 1/2 an inch more than that length. The fixings should have the requirements stated by the manufacturer on the packaging.
Drilling a Countersink or Countersunk Hole
There are two main reasons to countersink a screw head:
The first reason is to avoid catching or binding on anything when fastening down. For example, if using fasteners to attach a cabinet to the wall, you don’t want the screw to stick out.
The second reason is so that the countersunk screw fixings are hidden. This is useful if you want to match the surface material you are fastening to or don’t want anything to show.
Tapered bits are available, as mentioned above. You can use a drill bit slightly smaller than the screw head, then expand the hole to aid insertion.
The drilled holes will depend on the diameter of your screw head. As a result, it is difficult to offer precise drilling depths. But these procedures may be adapted to various lengths and equipment (handheld drills).
How to Set Countersink Drill Depth
There is no one-size-fits-all answer to this question. You need to set it to a fraction just below the surface.
There are a few ways of setting a countersink depth, but the drill press is the most accurate. With a pillar drill, you can ensure that the heads will be level for a flawless finish.
There are other alternatives to establish the desired depth. One way is to mark your regular drill bits with tape or paint. This is not as accurate, but it works if you’re careful.
A stop collar is a simple and inexpensive solution to make sure your fasteners are the same height.