What is a counterbore hole?

A counterbore (symbol: ⌴) is a cylindrical flat-bottomed hole that enlarges another coaxial hole, or the tool used to create that feature. Whereas a counterbore is a flat-bottomed enlargement of a smaller coaxial hole, a countersink is a conical enlargement of such.

How do you counter bore a hole?

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 a counter bore drill used for?

After the hole for the bolt or screw has been drilled, this counterbore is used to cut a larger hole around the first one. The counterbore shaft must be the same diameter as the bit used to drill the original hole, as it will guide the cutter to make a perfectly centered round recess.

What is a counterbored Mosin Nagant?

58 second clip suggested4:31Mosin Nagant Counterbore Barrel Explained – YouTubeYouTube

What is counter bore and counter sink?

A countersink is a cone-shaped hole that is cut into the PCB to allow the flat head of a socket cap screw to fit flush with the surface of the board. A counterbore is a cylindrical flat-bottomed hole that is designed to house a hex head or socket head cap screw to be used to secure a PCB board.

How do you use a counter bore and a pilot?

53 second clip suggested8:29Counterbores -How to make and use- – YouTubeYouTube

What is a spotface hole?

A spotface or spot face is a machined feature in which a certain region of the workpiece (a spot) is faced, providing a smooth, flat, accurately located surface. Zero-angle cutters obviate this, functioning similarly to the traditional counterbore cutters of manual machining but needing no pilot.

Why do we need to use countersink?

Countersinks are mainly used for countersinking drill holes, countersinking screws and deburring. Countersinking widens the drill hole and facilitates subsequent tapping. When countersinking screws, space is created for the screw head so that it closes with the surface of the workpiece.

What is counter boring a rifle?

59 second clip suggested4:31Mosin Nagant Counterbore Barrel Explained – YouTubeYouTube

How are counterbores made?

60 second clip suggested1:11Counterbore – YouTubeYouTube

What is a back counter bore?

The Back Counter Bore Tools were first Introduced and patented by Vermont Indexable Tooling in the late 1980’s and have since serviced thousands of both domestic and foreign Industries. The Back Counter Bore, or more commonly referred to as a Back Spot Facer, is a versatile tool that is intended to go thru a pre bored hole…

What is the back spot facing DIA of a tool?

Since a back spot facing tool is normally custom-built, there is no general thumb rule for the back spot facing dia with respect to the corresponding pilot dia. The holding shank can be cylindrical (suitable for side lock holders), Morse taper, ISO, BT, and Metric, depending upon the machine spindle taper.

How to use ABSF tool to cut the bore?

While rotating in anti-clockwise direction lower the ABSF tool into the bore. 3. Give some clearance from the bore’s lower face and rotate in clockwise direction for wing to fold out. 4. Rotating in clockwise direction begin the cutting feed.

What are the cutting parameters of the machine?

Cutting parameters depend on machine condition, clamping rigidity, hardness of job etc. For intermittent cutting, spindle speeds may almost be doubled, while feed rates are to be reduced by 30%. These are indicative parameters.