End mills are cutting tools widely used in milling. Most newer end mills are made from carbide. Therefore, these carbide milling cutters (carbide end mills) resist friction and wearing down more strongly than the high speed steel end mills that came before them. An end mill may also have a chemical composition coating so that it may further resist friction and wearing down.
The most common end mills are two-flute end mills and four-flute end mills. Both end mill types come individually or in sets. Usually, a two-flute end mill will be used to cut slots or grooves while four-flute end mills are used more for surface milling. Four-flute end mills can actually do most of the work that a two-flute end can, but a two-flute end mill cannot do most of the work a four-flute end mill can. However, each is better suited to certain types of metalwork projects.
Usually speaking, the fewer the number of flutes, the slower one has to feed the metalwork to the cutter. The more flutes there are the faster the feed will be. How many flutes and how quickly the feed must be also depends on the metalwork project. Obviously, four-flute end mills have faster feeds than two-flute end mills.
Also, two-flute end mills could be better for slotting since the two-flute cutter bites into both walls simultaneously and while cutting to the front cannot cut the sides. On the other hand, four-flute end mills will cut both the front and sides at the same time and the front cut will cause the cutter to flex, varying the side cuts’ depth, making the finish rougher. So four-flute end mills are better for finishing.
End mills are commonly used in metalwork projects involving machining aluminum. Regular end mills can be used with machine aluminum, but there are also specialized end mills just for this kind of metalwork project called high helix end mills. Their specialization gives a better finish. However, there are generally only two-flute end mills specialized for machine aluminum.
The number of flutes end mills have can help determine whether they are center-cutting end mills or non-center-cutting end mills. Some four-flute end mills are center cutting, meaning that two flutes meet in the middle and two do not. Obviously, two-flute end mills are center cutting, though no real reason exists why they have to be.
While shopping for end mills, one should also consider the differences between single-end mills and double-end mills. Double-end mills are less expensive since there are two cutting ends on the same cutting tool. However, one of these blades can become dull or damaged and it can go unnoticed because of the constant use of the good blade. Eventually, however, the bad blade will be used and the project is unintentionally harmed. A single end-mill’s mill can sometimes become jammed in an endmill adaptor and then driven out using a soft metal rod. The jamming of the single end mill would most likely damage the top end of a double-end mill.
With this knowledge, someone should be able to make the right considerations when selecting the proper end mill.
