General Information on Sharpening Metalworking Lathe Tools


Typical Grinding Media Used
  • DC-250 Diamond Wheel Course
  • CBN wheel : <100 grit
  • Very friable grindstone : 80 - 100 grit

Shaping the Tool - Metalworking lathe tools are typically reshaped based on their use. It is recommended that the metalworker get a set of tools for commonly used processes (e.g., a set for steel, one for aluminium, etc.).

Notes regarding shaping of tools with carbide inserts, when using a high speed grinder with a friable grindstone :

  1. DO NOT cool by dipping in water. This will cause the carbide to crack due to shocks.
  2. It is also recommended that you don't grind up to the final tool edge. The rough grit of the grindstone can create edges on the carbide which is easily susceptible to fractures.


Typical Grinding Media Used
  • SB-250 Black Grindstone, graded course
  • DC-250 Diamond Wheel Course
  • CBN wheel : 150-180 grit
  • Very friable grindstone : 150 - 180 grit

Sharpening the Tool - Metalworking lathe tools to be used for a job should be sharpened at the start of the job for which they will be used, and as often as necessary (which is more often than most people resharpen them).

As with shaping of tools with carbide inserts, when using a high speed grinder with a friable grindstone, DO NOT cool by dipping in water. This will cause the carbide to crack due to shocks.


Typical Grinding Media Used
  • SB-250 Black Grindstone, graded fine
  • DF-250 Diamond Wheel Fine
  • CBN wheel : 250+ grit

Honing the Tool - Many metalworkers do not hone their turning tools. Then there are others who sharpen and hone; and then re-hone again as much as possible (rather than resharpening). The type of metal which is being turned can determine this as well : softer metals benefit more from honing than do really hard steels.

My experience has been that rough turning can be done using a tool which is not honed; however the final cuts should be done with a tool which is honed. This provides for a smoother surface which requires less finishing (especially on soft metals like brass).