OVERVIEW

Even with the ever increasing use of carbide cutters for metal removal, the traditional HSS (high-speed steel) end mills still enjoy a great popularity for a variety of milling operations and even on lathes. These venerable cutters offer several benefits - they are relatively inexpensive, easy to find, and do many jobs quite well. The term high speed steel does not suggest much productivity improvement in modern machining, particularly when compared to carbide cutters. It was used long time ago to emphasize the benefit of this tool material to carbon tool steel. The new material of the day was a tool steel enhanced with tungsten and molybdenum ( i.e., hardening elements), and could use spindle speeds two to three times faster than carbon steel tools. The term high-speed-steel was coined and the HSS abbreviation has become common to this day.

The relatively low cost of high speed steel tools and their capability to machine a part to very close tolerances make them a primary choice for many milling applications. End mills are probably the single most versatile rotary tool used on a CNC machine.

The solid carbide end mills and end mills with replaceable carbide spiral flutes or inserts are frequently used for many different jobs. Most typical are jobs requiring a high metal removal rates and when machining hard materials. The HSS end mill is still a common cutting tool choice for everyday machining.

Many machining applications call for a harder tooling material than a high...