What is the purpose of countersinking a 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 counterbore hole?
A counterbore hole is defined as a cylindrical and flat-bottomed hole that usually enlarges into another coaxial hole. The hole is normally used whenever a fastener, for example, socket head cap screw, is needed to sit flush below or within the level of the workpiece surface.
What is the process of countersinking?
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 angle of countersinking for riveting?
75° for rivet heads. 82° for countersunk screws US standard. 90° for countersunk screws. 120° for countersinking of sheet metal rivets.
What is a threaded hole?
Threaded holes are integral aspects of mechanically fastened parts. They are easy to add with CNC machines. Threads are usually added last after most other aspects of the part have been machined. Getting it wrong and being forced to scrap a part can be a very costly mistake.
How do you counterbore holes?
To counterbore a hole, it’s easiest to drill the larger-diameter hole first, then drill the deeper hole for the fastener’s shaft. You should use a spade bit-or, better-a Forstner bit, which will create a flat-bottomed hole. It’s hard to say where the term counterbore came from.
What is countersinking in mechanical engineering?
In countersinking, a conical, reamerlike tool is used to cut a tapered enlargement at the opening of a hole for receiving the head of a fastener, for receiving a center, or for deburring. The surface cut by the tool is concentric with the hole and at an angle of less than 90° to it.
What is a countersinking drill bit?
A countersink bit creates an area in the wood that matches the countersunk shape of the screw head. This shape allows the screw to contact the wood with an equal amount of force. This creates a strong joint between the screw and the wood.
How is a threaded hole made?
Tapped holes are made in sheet metal parts by first starting with a laser cut hole. That hole is then treated with a treading bit to create threads in the hole for use with a screw or bolt with matching threads to hold a component or attaching the sheet metal part to another component.
What is the meaning of a bolt hole?
a place of escape or refuge
Definition of bolt-hole chiefly British. : a place of escape or refuge.
What are the types of holes?
Terms in this set (5)
- Blind Hole. A hole that does not go completely through the workpiece.
- Taper. Gradual diminution of width or thickness in an elongated object.
- Counter Bore. A cylindrical recess around a hole, usually to receive a bolt head or nut.
- Tapped Holes. Has internal threads.
- Countersink.