Machine shops offer, among many different services, turning operations. This involves the removal of metal or other material from the outer diameter of a workpiece as it rotates. The purpose is to create a circular shape or cylindrical surface with a single point tool. Over the years, while the goal has remained the same, the tools have changed to reflect technological advances.
Early Turning Tools
One of the early tools for machinist performing a turning operation were single-pointed, solid, rectangular pieces of high-speed steel (HSS) with rake and clearance angles only on one end. Prior to this, the tools commonly were composed of high-carbon steel. HSS tools offered a distinct advantage with their ability to withstand much higher temperatures and yet retain their hardness (temper). Other qualities included:
- Faster speed of cutting
- Higher hardness levels
- Greater abrasion resistance
However, issues remained concerning the ongoing need to sharpen them. A dull HSS tool requires sharpening, generally employing a pedestal grinder.
Carbide tools offered further improvement. For turning operations, they offered machinists the chance to improve their capabilities and production speed. Carbide turning tools, compared to their predecessors, offer:
- Improved wear resistance
- Increased tool longevity
- Enhanced productivity
However, like HSS turning tools, carbide tools require sharpening. While not as frequently, they are not conducive to fast turnover. They require the use of a diamond wheel and special training and experience in using it.
Tools for Turning Operations Today
While some machine shops still employ HSS tools and carbide, others are currently utilizing better technology to improve productivity and reduce the necessity of retooling and maintenance. Tool holders with coated or uncoated carbide inserts mechanically locked into place are common in workplaces. CNC turning machines make multi-axis turning operations simple. Using carbide inserts, they operate with CAM to provide machinists with more options than ever before. In the hands of a skilled operator, they simplify what was once complex.