9.7 Tooling
Micky R. Jennings
Tooling is a term used to talk about the tools used on machinery to cut the parts. On milling machines, the tooling might look similar to that of a drill press; however, aside from hole making tooling, the tooling designed for a milling machine is very different. Specifically, milling machine tooling is designed to cut horizontally. Because of the capability of the milling machine to facilitate sideways cutting, the machinist can create flat, straight sides and rectangular parts. The tooling for a milling machine consists of a variety of different designs that allow the machinist to create different shapes for the features that may be required of a part.
Tooling Materials
Tooling for milling machines can be made of several different materials. High speed steel (HSS) is often considered the baseline material for tooling in a machine shop and is typically used on manual milling machines because it is an economical material for end mills and other rotary tooling. Generally, machine tools for cutting metal will never be of a quality less than HSS; however, there are many materials that have properties greater than HSS that are occasionally used on manual milling machines (Beaumont, n.d.). Cobalt tooling has a higher percentage of cobalt in its alloy than regular HSS. It can be used effectively to machine harder alloy steels and stainless steel. Carbide is another very popular tool material for its additional rigidity and heat resistance. In addition to base materials, coatings on tooling are a huge part of selecting a tool. Some tools are also made with an alloy steel body and indexable insert cutting edges. This design makes these tools more economical than a solid carbide tool.
Face Mill
A modern day face mill has many indexable carbide inserts that are designed to cut the top of the work. This cutting action is called facing. Face mills can be as small as 1″ in diameter or as big as 10″or larger. For manual equipment, 1″- 3″ face mills will be the most common. It is advised to use face mills with a high positive rake because of the relatively low horsepower of many vertical manual milling machines. Neutral or negative rake face mills or face mills over 3″ are only recommended for use on larger, more powerful machines. For facing cuts over 3″ in diameter, a fly cutter would be a better tool than a face mill.
End Mill
An end mill, despite its name, does a majority of the cutting on the side of the tool. At first glance, the end mill looks similar to the twist drill, but that is where the similarities end. Some end mills are referred to as “center cutting” and are capable of plunge milling with the end of the tool, but this isn’t the tool’s main function. On a milling machine, end mills do a majority of the shaping of parts. From contours and angles to slots, grooves, and bosses, end mills are a very versatile tool. End mills come in a few different styles, rougher, finishing, inserted, ball nose, bull nose, 2- flutes to