Lathe parting tool: Angles,types

Introduction

• Parting or cutoff is the operation of cutting a piece off by slicing a groove all the way through it when a special parting or cutoff tool.
• Parting tools are generally thin blades of HSS, but there are also carbide insert tools available for the task or you can grind a cutoff tool out of HSS.
  

Parting/cutoff Tool and Angles

• whenever parting to be sure to use plenty of coolant, such as a sulfurized cutting oil.
• Parting tools normally have a 5 degree side rake and no back angles.
• The blades are sharped by grinding the ends only.
• It is also used to cut off work after other machining operations have been completed.
• These tools can be of the forged type, inserted blade type, or ground from a standard tool blank.
• To maximum strength, the length of the cutting portion of the blade should extend only enough to be slightly longer than half of the work piece diameter ( able to reach the center of the work).
• To be sure parting cut at a right angle to the centerline of the work.
• 

Parting Tools Types W.R.T Shape

Chatter

• Parting often causes “chatter” . It is a pulsing vibration that can shake the whole lathe and even cause it to move around on the workbench if is not bolted down.
• You can stop chatter quickly by draw back the pressure on the tool. 

Tips To minimize chatter

Here are some tips to minimize chatter.

• Tool tips should be quite sharp
• Top of tool should be right Angle on the lathe machine.
• Tool should be perpendicular to the work piece.
• Saddle should be tight to the ways.
• Use carriage lock to lock saddle to ways.
• Use cutting fluid.
• Maintain steady advance of cross-slide.