Why use countersink

However, there are important differences between the two which makes it important to understand when to use one or the other. Counterboring and countersinking are done on top of a drilled hole to allow the screw or bolt head to stay below the surface of the workpiece. The most noted difference between a countersink and counterbore is the size and shape of the screw or the tool which creates the holes in the material. A counterbore hole is deeper and has a square-like shape where the shoulder of the screw head can seat.

It also allows for the addition of washers to be used. A countersink will create a conical-shaped hole that is identical to the angled shape found on the underside of a screw which has a flat top. The hole can vary in depth so that the flat head can rest even with the surface or be driven in deeper and covered with a plug to hide its appearance. So, while both are used to set a fastener below the surface of the material, the shape left behind at the bottom of the hole is different.

A counterbore will create a hole that is flat on the bottom. This will allow the bolt or screw that has a flat underside as opposed to the angled shape of a countersink to rest inside. A washer is often used in this situation. It should be noted that the hole created by a counterbore is normally larger than the head of the screw which allows for a washer to be placed. Bothe countersinking and counterboring are done co-axial to the screw hole, the difference in their geometry.

The cutting tool used for machining countersink hole is called a countersunk or a countersink bit. The 90deg countersink tool is also used to chamfer hole edges. To remove these burrs the countersink is used which deburrs the edge of the hole, i.

In principle, however, deburring can be carried out with any countersink angle. Especially when drilling metal a burr is formed. This can be very sharp-edged and represent a risk of injury. Therefore you should remove the burr after drilling. Not only for safety reasons but also to enhance the appearance of the drill hole. The countersinking of the hole widens the entry area and facilitates the insertion of a thread drill, for example.

How to cut an internal thread is explained in our article " How to cut an internal thread in 3 steps ". To countersink a screw flush with the surface of the workpiece, a countersink is used.

The final result is as follows. The special feature of this countersink is a drill hole across the countersink. This hole through the head thus forms two cutting edges. The chip is transported away via the hole , which prevents them from getting jammed between the drill and the workpiece. Cross-hole cutters are also extremely seldom caught in the material. With a cross-hole core, clean results can be achieved and are easy to handle. The countersink is free of burrs and chatter.

With the cross-hole core you can also make countersinks for the countersunk screw. Flat countersinks have a cylindrical shape compared to countersinks. Countersinks are used to produce countersinks for cylinder head screws, hexagon head screws and nuts. At its tip there is a fixed guide which is inserted into the pre-drilled hole.

This ensures a stable guidance of the drilling machine and precise working. These doubled ended tools are used to produce a center in the end of a round product so that the part can be held between centers on a lathe or CNC machine. Skip to main content.

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This article has been viewed , times. Learn more Countersinking a screw helps the screw head lie flush with the surface of the wood to better conceal the hardware. If you want to make your next woodworking project look clean and professional, you can easily countersink the screws with just a few tools. Start by drilling a pilot hole for your screw so you can thread it in easily without splitting the wood. After that, you can use a countersink cutter to drill a larger hole for the screw head.

Once the screw is in place, you can either leave it exposed or conceal it using wood putty! Countersinking a screw helps it lie flush with the surface of the wood to hide the hardware.

Clamp your wood down to secure it, then put a dot where you want to make your hole. Slowly drill into the pilot hole with the cutter to make your countersink. Finally, use your drill to secure the screw into the hole until the top is flush with the wood. To learn how to hide your screw with wood putty, keep reading! Did this summary help you? Yes No. Log in Social login does not work in incognito and private browsers.

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