How do you specify a countersink hole?

How do you specify a countersink hole?

Write the dimensions of the countersink, giving first the diameter of the drill hole, then the angle of the countersink, followed by the diameter symbol and the diameter of the larger hole.

What is the purpose of a countersink hole?

Countersinking is done to insure that flat head screws sit flush to the work piece. A countersink produces a conical hole matching the angle of the screw so that when the screw is fully engaged the head will sit flush or slightly below the surface.

What is a countersink hole in engineering?

What Are Countersunk Holes Used For? Countersunk holes are used for applications where a countersunk bolt or screw is required. Like counterbore holes, countersink holes ensure the bolt or screw sit below the surface.

How do you use a countersink symbol?

Countersink symbol If you want to type the ⌵ symbol, hold the ALT key and press 9013.

Why is it called countersink?

They are called “countersunk screws” because they “sink” into objects and surfaces. They feature a flat head that tapers along the shaft. Therefore, when you drive a countersunk screw into an object or surface, the head will sink so that it’s flush with the respective material.

What countersunk means?

countersink. / (ˈkaʊntəˌsɪŋk) / verb -sinks, -sinking, -sank or -sunk (tr) to enlarge the upper part of (a hole) in timber, metal, etc, so that the head of a bolt or screw can be sunk below the surface. to drive (a screw) or sink (a bolt) into such an enlarged hole.

Which symbol means countersink hole?


A countersink (symbol: ⌵) is a conical hole cut into a manufactured object, or the cutter used to cut such a hole.

What is a countersink in construction?

What Does Countersinking Mean? Countersinking a hole is to cut a conical hole into a metal object. This process is normally used to create space for the head of a screw or bolt to sit flush with the surface of the material or to clean away burrs left from drilling and tapping.

What does countersink mean in construction?

Countersinking a hole is to cut a conical hole into a metal object. This process is normally used to create space for the head of a screw or bolt to sit flush with the surface of the material or to clean away burrs left from drilling and tapping.

What is a countersink tool?

A countersink is a cutting tool that cuts a conical hole into a base material and can be used for a number of different applications. The main use of countersinks is to cut a hole to allow the head of a countersunk screw or bolt, when fastened into the hole, to sit below or flush with the surface of the base material.

How do you draw a countersunk hole in Autocad?

From the ribbon, Content tab, Holes paneldrop-down, select the Countersink icon, which is the second from the left on the bottom row. Again, you have the choice to use either a user-defined countersink, or a countersink to match a standard fastener. I’ll choose ANSI Countersinks, then the Top view.

How do you measure the angle of a countersink hole?

Since the countersink has a 90° included angle, bisect that angle with the centerline of the hole to create two equal 45° angles. Subtract the existing hole diameter from the countersink diameter. Then divide the answer by two because ½ the difference is on each side of the hole.

What is countersink process?

Countersinking is a process that creates a V-shaped edge near the surface of a hole. It is often used to deburr a drilled or tapped hole, or to allow the head of a countersunk-head screw to sit flush or below a surface. Chamfering endmills are commonly used to make countersinks when CNC milling.

What is the size of a countersunk hole?

For example, an ANSI Inch 1/2″ flat head screw with a normal fit countersunk hole will require a pilot hole diameter of 9/16″, a countersunk diameter of 1″, and a countersunk angle of 82°. All dimensions are in inches apart from the countersink angle. If you want to learn more about countersunk holes, see our post here.

How do you write the dimensions of a countersink?

Write the dimensions of the countersink, giving first the diameter of the drill hole, then the angle of the countersink, followed by the diameter symbol and the diameter of the larger hole. This dimension can be given either with a diameter symbol first, or with the word DRILL after the first diameter.

Why is it important to know the depth of countersink hole?

It is important to know the depth of countersink hole,it will be drilled into the layer which need be cut copper at inner and outer layers for NPTH,and whether it affects electrical performance for PTH.Usually the depth tolerance also need to be taken into account when calculating depth of countersink hole.

What defects can occur when drilling countersunk holes?

However, a number of different defects can occur when drilling countersunk holes, i.e. countersunk hole is drilled too deep causing the bolt head to sink below the aerodynamic surface of the component.