Page 140 - Turner 1st sem Practicals

Clamp the internal chamfering tool and chamfer the edges
of the recess to remove the burrs. (Fig 10)

Form a recess

Objectives : This shall help you to
• set the recessing tool in the tool post
• set the tool at the required position
• perform different types of recesses
• check the recess using an inside caliper.

Recessing Turn the cross-slide handle so that the front of the tool
Recessing is the process of cutting an annular channel just clears the wall of the bore.
inside the bored hole. Turn the top slide handle to position the tool at the
To perform recessing, the following procedure is to be calculated distance into the bore.
followed. If a feeler gauge has been used in the above

Select an internal recessing tool of correct width. procedure, allow for the thickness of the gauge
when calculating the distance to move the top
Check that the tool and/or boring bar will clear the work of slide.
the bore.

Mount the tool on the tool post. Turn the cross-slide hand wheel in an anticlockwise
direction to advance the tool and touch the bore.
Align the face of the tool to the wall of the bore.
Note the cross-feed graduated collar reading.
Calculate the distance from the face to the edge of the
groove farthest from the end face. Rotate the cross-slide hand wheel in the same direction
to make the tool remove the metal from the bore to form
Turn the top slide handle back to ensure that the slide can the recess.
move the required distance.
Feed the tool slowly and continuously till the calculated
Touch the tool edge to the face of the workpiece using the division of the cross-slide reaches the zero mark.
top slide handle.
Reverse the direction of rotation of the cross-slide hand
The tool may be made to contact the feeler gauge held wheel and make the cutting edge clear the diameter of the
between the edge of the tool and the face of the workpiece. bore.

Set the compound slide graduated collar to zero. Retract the tool by moving the saddle towards the tailstock.

Producltion & Manufacturing : Turner - Exercise 1.3.39 127