Scribd
Upload
527 views5 pages

Cutting Parameters

The document discusses key formulas for determining cutting speed, feed rate, depth of cut, and machining time in lathe operations. It defines cutting speed as the rate at which material is removed from the workpiece by the tool, usually measured in meters per minute. Feed rate refers to the distance the cutting tool advances along the workpiece per revolution, measured in millimeters or inches per revolution. Depth of cut is the perpendicular distance from the finished surface to the unfinished surface of the workpiece. Machining time can be calculated based on feed rate, length of workpiece, and revolutions per minute.

Uploaded by

abdulwaseh0292
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
527 views5 pages

Cutting Parameters

The document discusses key formulas for determining cutting speed, feed rate, depth of cut, and machining time in lathe operations. It defines cutting speed as the rate at which material is removed from the workpiece by the tool, usually measured in meters per minute. Feed rate refers to the distance the cutting tool advances along the workpiece per revolution, measured in millimeters or inches per revolution. Depth of cut is the perpendicular distance from the finished surface to the unfinished surface of the workpiece. Machining time can be calculated based on feed rate, length of workpiece, and revolutions per minute.

Uploaded by

abdulwaseh0292
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
You are on page 1/ 5

Lathe machine formula for cutting speed,

feed and depth of cut, machining time.


1. Cutting Speed
The cutting speed (v) of a tool is the speed at which the metal is
removed by the tool from the work piece.
Rate at which material is removed
by tool.
expressed in meters per minute.
d – is the diameter of the work
in mm / inches.
n – is the r.p.m (revolution per minute) of the spindle.
As diameter (d) is in mm so we have to divide the equation by 1000 to
convert it into meters (1/1000 mm = 1 meter) Example 1)
A steel shaft of 25mm diameter is turned at a cutting speed of 50 metres
per minute. Find the r.p.m. of
the shaft.
In practice, when the
calculated speed is not
available in the machine the
next lower value is selected.
If a cutting speed is too high, the cutting tool edge breaks down rapidly,
resulting in time lost recondition the tool. With too slow a cutting speed,
time will be lost for the machining operation, resulting in low production
rates.
2. Feed
The feeds of the cutting tool in lathe work are the distance the tool
advances for each revolution of the work
OR
the distance the tool travels during one revolution of the part
OR
the distance the cutting tool advances along the length of the work for
every revolution of the spindle
A feed is expressed in millimeters / inches per revolution.
Rough cut is to remove excess material quickly and surface finish is not
too important. A coarse feed should be used. The finishing cut is used to
bring the diameter to size and produce a good surface finish and
therefore a fine feed should be used.
Increased feed reduces cutting time. But increased feed greatly reduces
the tool life.
3. Depth of Cut

The depth of cut (t) is the perpendicular distance measured from the
machined surface to the uncut surface of the work piece.
d1 – diameter of the workpiece
surface before machining.
d2 – diameter of the machined
surface.
the depth of cut changes
inversely as the cutting speed.
normally in inches or millimeters.
4. Machine Time

If “F” is the feed of the job per revolution expressed in mm per revolution
and “L” the length of the job in mm, then a number of revolutions of the
job required for a complete cut will be: L/F.

If the r.p.m. of the work is n, the time is taken to revolve the job through
𝐿
l/s number of revolutions for a complete cut will be: T = 𝐹×𝑛

If L=100mm, F = 2mm, Then L/F = 50 Revolutions


How much time is required to complete 50 revolutions with feed 2 mm to
cut length of 100mm?????
Find the time required for one full cut on a workpiece of 350mm long and
50mm in diameter. The cutting speed is 35 metres per minute and the
feed is 0.5mm per revolution.

You might also like