What’s the difference between left and right end mills?


The milling cutter is the most important tool of CNC machine tools. There are many kinds of milling cutters we use in our daily life, and end mills are the most common. End mills can be divided into left-hand milling cutters and right-hand milling cutters. Do you still have no idea of milling cutter turning left and right? As a metal cutting tool supplier, UKO specializing in the production of carbide CNC inserts, cermet CNC inserts, end mills, and etc. Today we are going to discuss the difference between a left-handed end mill and a right-handed end mill.

How to judge the left-handed and right-handed end mill?

To judge whether the milling cutter is left-handed or right-handed, we can use the following methods. Put the edge of the milling cutter vertically upward. If the rising direction of the cutting edge is low left and high right, that is, from left to right, it is a right-hand milling cutter. We can clench our fists and stretch out our thumbs. The rising direction of the cutting edge groove is the same as that of the right thumb, which means that if the cutting edge groove rises from the bottom right to the top left, it is left rotation.

Schematic diagram of how to distinguish left and right rotation of end milling cutter

We can see that when the screw rotates if it is forced not to “screw in”, the nut will enter. Compared with a milling cutter, it is the metal debris cut. Therefore, when the milling cutter rotation direction is unchanged, the chip removal direction of the left and right milling cutter will be different.

When milling, the rotation direction of the left milling cutter must be consistent with that of the right milling cutter, so that the direction of chip removal can be changed. For the purpose of changing the chip removal direction, the direction of the cutting edge of the left-hand milling cutter needs to be the same as that of the right-hand milling cutter, that is, “right-hand cutting”, that is to say, the chip removal mode of the right-hand milling cutter is opposite to that of the left-hand milling cutter.

ItemRight-handed end millLeft-handed end mill
Shaperight-hand helixleft-hand helix
Direction of rotationcounterclockwiseclockwise
Tool feed directionto left sideto right side
Applicationgeneral millinghigh-precision processing requirements of chip removal
Difference between right-hand end mill and left-hand end mill

Application of left-hand milling cutter

Generally, the left-hand milling cutter is a kind of tool that can only be selected for the high-precision processing requirements of chip removal, such as film switch panel, key processing of mobile phone, acrylic lens, and LCD panel. But there are some high requirements, especially some mobile phone buttons or electrical panel processing, high finish requirements are also very high, you need to choose the left-hand milling cutter with chip removal.

What are the advantages of chip removal under the left milling cutter? In this way, the surface of the workpiece is not cleaned. Cutting force down hard, will not lift the workpiece, the workpiece is not easy to shift. The lower chip removal can also avoid the phenomenon of knife-edge whitening and edge skipping of machined parts.

Application of right-hand milling cutter

In the whole manufacturing industry, the right-hand tool is usually used for machining. UKO’s customers, whether domestic or foreign, most of the right-hand cutting tools are purchased. For the milling cutter, the groove of the tool body determines the discharge direction of the cutting debris. However, if the parts are made of precision parts and there is space for chip removal below, it is recommended to use a left-hand milling cutter. The left-hand milling cutter has certain advantages in processing precision parts with special requirements.

About the left and right rotation of end mill, if you have other opinions, please share with UKO. If you have any demand for end mills, you can also contact us at any time. We not only produce carbide end mills, but also HSS end mills. In addition, our carbide milling inserts have good feedback of customers, welcome to inquiry.

You May Also Like