Difference Between Counterbore and Countersink

Construction work is not an easy task. One small mistake will lead to bigger consequences. There are two tools available for making the woodworking and the construction work smoother. One is Counterbore, and the other is Countersink. They are very useful and used in wide areas. The best part is we can even make the designs using Counterbore and Countersink tools on the computer.

Counterbore vs Countersink

The main difference between Counterbore and Countersink is counterbore is a circular hole, and it has sections that are used at different diameters. Countersink is conical in shape, which can be cut into objects. The size of the hole in the counterbore will be bigger. The size of the hole in the countersink will be smaller when compared to the counterbore. 

Counterbore and Countersink

The Counterbore has a pilot that will keep it in the center for ensuring the level seat. One of the advantages of using a counterbore will help in opening the large holes so that the screw can easily fit. They are used only for a single purpose. The cutting edges in the counterbore can be either straight or spiral teeth. A counterbore is a cylindrical recess. 

A countersink is used to allow the head of a countersunk bolt. During the drill work, it creates an area in the wood so that it matches the shape of the screw head. Countersinking a screw means you are going to drive the screw below the surface. The head of the countersink will sink into the workpiece’s surface. If you notice it carefully, you can see that it tapers towards the shank. 

Comparison Table Between Counterbore and Countersink

Parameters of ComparisonCounterboreCountersink
ShapeCylindrical flat-shapedCone-shaped
Size of holeIt is bigger than a countersink.It is smaller than a counterbore.
DefinitionIt is a circular hole with sections at different diameters.It is a conical hole that is cut into an object.
UseIt is good for holding strength.It is good for holding stronger objects.
Good forWoodworking and thin sheet metalAutomotive and construction

What is Counterbore?

It is a drilled hole having a wider section at the top area. It is used for cutting the spot face. To make the surface flat, a small amount of material will be used. It is also used for creating a perpendicular surface on a non-perpendicular surface. The main types of counterbores are aircraft counterbores, fillister head screw counterbores, back counterbores, cap screw counterbores, and blade counterbores. The drill in the counterbore is made of solid carbide.

The drills have four flutes with 15 helices. The user can select the correct one depending on the tool chart given before the purchase. The shape of the counterbore is cylindrical flat shaped. The hole in the counterbore has a flat bottom, and it allows a screwer or fastener to fit inside it. Any instrument made in this form is called Counterbore.

The counterbore is also used for drawing purposes. It has a hole that provides the recess for the head of the screw. It can be a flat surface for exposed nuts or bolts. For making counterbore in shapes, you need to create a sketch in sketch points. You need to select the points where you would like to create holes. Finally, you need to select the hole style. A manufacturer can hide the fastener completely during the entire journey process of the counterbore. 

What is Countersink?

It is a conical hole cut into a manufactured object. It is for ensuring that the acres sit flush to the workpiece. It will match the angle of the screw by matching the conical hole. When the screw is fully engaged, it will sit tightly or below the surface. There is a relation between the countersink and drill. Countersinks are used for countersinking drill holes. It helps to widen the drill hole, which will facilitate the subsequent tapping.

It is called a countersink because the screw will be sunk into the countersink. Countersink has been manufactured with six angles such as 120, 100, 82, 90, 60, and 110. The two most common angles used in the countersinking process are 82 and 90. But in the aerospace industry, they use 100 for fasteners. During MDF fastening, the countersink plays an important role in preventing the holes from mushrooming. For this, you have to drill countersinks on both faces. 

And it should also be drilled on the mating surface of the mating piece. This helps the parts to sit fully and provides relief to all the parts. Countersink is mainly used in removing burrs that are left from drilling or tapping operations. A coach bolt can be countersink so that it makes a shallow hole in the wood. This will make a flat part so that the head of the bolt will fit in. The advantage of using a countersink is it will increase the structural lifetime and also protects them. 

Main Differences Between Counterbore and Countersink

  1. The shape of the counterbore is cylindrical flat shaped. On the other hand, the shape of the countersink is conical shaped. 
  2. The size of the hole in the counterbore will be bigger than the countersink. On the other hand, the size of the hole in the countersink will be smaller than the counterbore.
  3. A counterbore is a circular hole that has sections at different diameters. On the other hand, the countersink is conical which has been cut into an object.
  4. The advantage of using a counterbore is it is good for holding strength. On the other hand, the advantage of using a countersink is it is good for holding stringer objects.
  5. The counterbore is mainly used in woodworking and thin sheet metal. On the other hand, the countersink is mainly used in automotive and construction.


Both of them are good at construction and woodworking. The best part about them is they are used for drilling purposes as well. This makes the work to be done smoothly without any difficulties. These tools are available in computer-aided design. Students who work in the design area might know about this. They used this tool in the computer to draw the design.

The design can be made in simple steps by selecting everything from the computer-aided design. The counterbore is mainly used by people who work in the area of the woodwork and also in thin sheet works. They use these tools to make them work faster, and it will also give a clean look. Countersink is done by people who work in automotive sites. 


  1. https://iopscience.iop.org/article/10.1088/1755-1315/632/4/042068/meta
  2. https://ieeexplore.ieee.org/abstract/document/8599335/
AskAnyDifference HomeClick here
Search for "Ask Any Difference" on Google. Rate this post!
[Total: 0]