Different shapes of tools have different uses. Let's take a look at the uses of various shapes.

Almost all milling cutters can be used for traditional low-speed milling, but when used for high-speed cutting or "high performance" applications involving fast cutting and more strokes, the performance differences between the various tools appear It matters. Specially shaped tools have special uses.

This article will introduce some tips on how to effectively use tools of different shapes. The four basic tools mentioned here are widely used in 3D milling and profiling milling, but there are many special applications within these wide range of uses, and a particular tool may have higher efficiency. At least some of these tools are worth using in applications that are not normally considered.

Square shoulder end mill

An important point in understanding the use of square shoulder end mills is that the heat generated during cutting can easily accumulate at the tip of the square. In high-speed milling, the cutting speed may have to be reduced in order to slow down the excessive wear of the corners caused by heat generated during cutting. When milling hardened metal, this tool is only suitable when the tip is not involved in cutting. For example, the vertical side wall surface of a precision milled flat bottom part. When milling unheat-treated metals, typical applications include rough and fine milling of vertical walls.

Square shoulder end mill with rounded corners

A square shoulder end mill with a rounded tip allows higher cutting speeds because the heat generated by the cutting can spread to a larger area on the tool. Like the square-shoulder end mills with round tips, typical applications for these tools include rough and finish milling of vertical walls of unheated metal. In addition, the tool can also be used for fine milling of heat-treated metal vertical walls, whether flat or bottom. If you need to process into a small arc, you can also use this type of tool to clear the root. Another application of square shoulder milling cutter with round tip is cycloidal machining. This is a tool path with continuous arc feed for a fixed arc radius. (See the illustration at the bottom left) Sharp-angled square shoulder milling cutters can only be used for cycloidal machining without a bottom, while rounded-pointed square shoulder milling cutters can perform various cutting depth cycloidal machining. As shown in the upper left picture, the shape of the bull nose knife is different. Don't confuse bull nose knife with a copy milling cutter with multiple round inserts. The round blade copy milling cutter does have important uses, but because of the multiple blades, this type of cutter does not have the machining accuracy that the bull nose cutter has. Bull nose cutters are used for rough milling of cavities and cores under moderate cutting speeds and relatively high cutting loads. A better use of the bull nose knife is to finish milling planes, including parting surfaces.

Ball end mill

In my opinion, the ball nose milling cutter is the most common tool for high-speed machining. Ball-end milling cutters can be used for roughing any cavity, core and three-dimensional shape. They can also be used to finish any material in all hardness ranges. Because of the spherical shape, the heat generated by cutting can be absorbed into the tool in a large area, and this tool allows a higher cutting speed than other tools. It also allows for a greater depth of cut because the spherical cutter can direct a greater cutting force component toward the spindle when the rigidity is high, and to the side when the rigidity is poor. For the same reason, reducing tool vibration further helps control heat. If we consider the advantages of this type of tool in terms of cutting speed and depth of cut, the ball nose milling cutter has a higher metal cutting rate than the other milling cutters introduced in the article.

For rough milling of heat-treated materials, ball-end mills are often the tool of choice. If you need a small fillet radius, you can then use other types of tools to clean the corners.

When milling slots, pockets and ribs, cylindrical end mills are often used because the shape of this tool seems to match each of these features. But in fact, the ball head milling cutter is also competent for the above tasks. For example, if a ball-end mill is used to process a deep groove (whether through or closed), typical high-speed machining techniques such as shallow slope milling and contour milling can be used. Processing grooves in this way is much faster than milling with cylindrical end mills. Also, the side walls of other parts of the part may have better straightness and perpendicularity, unlike the taperedness usually caused by bending with an extended cylindrical end mill. Reinforcement ribs can be processed using similar methods. Application of milling 3/4 inch wide grooves on P20 steel 5 inches long and 2 inches thick. The intersecting holes in the middle of the part produced intermittent cutting. It takes 30 minutes to process 6 slots using the original milling method, which does not include the time for rough milling. But after using the ball-end milling cutter combined with high-speed machining technology, a total of 6 slots including rough milling and fine milling takes only 10 minutes.