By choosing the right milling cutter, using rolling cutting in face milling, and using the milling cutter for hole machining under the right conditions, manufacturers can 

significantly increase production capacity and processing efficiency without investing in new equipment, saving a lot of money. time and cost.

Milling cutter main angle:

The main inclination angle is the angle between the cutting edge and the cutting plane. The main inclination angle has a great influence on the radial cutting force and 

cutting depth. The size of the radial cutting force directly affects the cutting power and vibration resistance of the tool. The smaller the main inclination angle of the milling 

cutter, the smaller the radial cutting force and the better the vibration resistance, but the cutting depth also decreases.

When milling a square shoulder plane, select a 90° lead angle. This tool has good versatility and is suitable for single piece and small batch processing. Since the radial 

cutting force of this type of tool is equal to the cutting force, the feed resistance is large and it is easy to vibrate, so the machine tool is required to have greater power and 

sufficient rigidity.

When machining square shoulder planes, a milling cutter with a main angle of 88° can also be used. Compared with 90° main angle milling cutters, its cutting performance 

has been improved. It is also common to use 90° square shoulder milling cutters for face milling. In some cases, this choice makes sense. Irregular shapes of the workpiece 

being milled, or casting surface will cause changes in the depth of cut. A square shoulder mill is probably the best choice. But in other cases, a standard 45° face mill may 

benefit more.

When the cutting angle of the milling cutter is less than 90°, the axial chip thickness will be less than the feed rate of the milling cutter due to the thinning of the chip. The 

cutting angle of the milling cutter will have a big impact on the feed available for each tooth.

In face milling, a face milling cutter angle of 45° will result in thinner chips. As the cutting angle decreases, the chip thickness will be less than the feed amount of each tooth, 

thereby increasing the feed speed to 1.4 times the original. The radial cutting force of the 45° leading angle milling cutter is greatly reduced and is approximately equal to 

the axial cutting force. The cutting load is distributed over the longer cutting edge. It has good anti-vibration properties and is suitable for boring and milling machine 

spindle suspension. reprocessing situations. When using this tool to process flat surfaces, the blade has a low breakage rate and high durability; when processing cast iron 

parts, the edges of the workpiece are not easy to peel off.

Milling cutter size selection:

The diameter of standard indexing face milling cutter is Φ16~Φ630mm. The diameter of the milling cutter should be selected based on the milling width and depth. Generally

speaking, the greater the depth and width before milling, the larger the diameter of the milling cutter. During rough milling, the diameter of the milling cutter of the milling 

machine is smaller; during finishing, the diameter of the milling cutter is larger, trying to adapt to the entire processing width of the workpiece and reducing the traces of tool 

connection between two adjacent feeds.

When face milling large parts, they use milling cutters with smaller diameters, which leaves a lot of room for increased productivity. Ideally, a milling cutter should have a 

cutting edge of 70%. Tool size becomes particularly important when milling holes with a milling cutter. If the diameter of the milling cutter is too small compared to the 

diameter of the hole, a core can then be formed in the center of the hole during machining. When the core falls, it can damage the workpiece or tool. If the diameter of the 

milling cutter is too large, it will damage the tool itself and the workpiece because the milling cutter cuts in the center and may collide at the base of the tool.

Choice of milling method:

Another way to improve the milling process is to optimize the milling strategy of the face milling cutter. When programming face milling, the user must first consider how 

the tool will penetrate the workpiece. Typically, the milling cutter simply cuts directly into the workpiece. This cutting method is usually accompanied by loud impact noise 

because the milling cutter produces the thickest chips when the insert is pulled out. Because the blade has a large impact on the workpiece material, it often causes vibration 

and produces tensile stress, thereby shortening the life of the tool.

A better feeding method is to use the hobbing method, that is, the milling cutter rolls into the workpiece without reducing the feed speed and cutting speed. This means 

that the milling cutter must be rotated clockwise to ensure a milling pattern. The chips formed in this way are from thick to thin, which can reduce vibration and tensile stress 

on the tool and transfer more cutting heat to the chips. By changing the method, the milling cutter can cut into the workpiece every time, and the tool life can be extended 

by 1-2 times. To achieve this feed method, the programmed radius of the tool path should be 1/2 the diameter of the milling cutter and increase the tool offset distance from 

the workpiece.

While rolling cutting methods are primarily used to improve the way the tool cuts into the workpiece, the same machining principles can be applied to other stages of milling. For large area face milling, a common programming method is to have the tool pass through the entire length of the workpiece one after another and then complete the next cut in the opposite direction. To maintain a constant radial feed and eliminate vibration, better results are often achieved using a combination of helical downcutting and roll milling of workpiece corners.

Machinists are familiar with cutting noise caused by vibration. It usually occurs when the tool cuts into the workpiece, or when the tool makes a sharp 90° turn while feeding. 

Hobbing workpiece corners can eliminate this noise and extend tool life. In general, the corner radius of the workpiece should be 75%-100% of the diameter of the milling 

cutter, which can shorten the arc length of the milling cutter, reduce vibration, and allow the use of higher feed speeds.

In order to extend the service life of the tool, during the end milling process, the tool should be kept as far away from the hole or interrupted part of the workpiece as 

possible (if possible). When the face milling cutter passes through the middle of the hole in the workpiece, the tool mills along one side of the hole and counter-mills on the 

other side of the hole, which will cause a great impact on the insert. This can be avoided by bypassing holes and pockets when programming the tool path.

Use milling down or milling up:

An increasing number of manufacturers are using milling cutters to machine helical or circular interpolation holes. Although this method is slightly slower than drilling, it is 

beneficial for many processes. When drilling on irregular surfaces, the drill bit may have difficulty drilling along the centerline of the workpiece, causing the drill bit to drift 

across the workpiece surface. Also, for every 25mm of hole diameter, the drill bit requires about 10 horsepower, which means that when drilling on small power tools, the 

optimal power value may not be achieved. In addition, some parts require the machining of many holes of different sizes. If the tool magazine has limited tool magazine 

capacity, the use of milling holes can avoid frequent machine tool shutdowns due to tool changes.

Tool size becomes particularly important when milling holes with a milling cutter. If the diameter of the milling cutter is too small relative to the diameter of the hole, a core 

can be formed in the center of the hole during machining. When the core falls, it can damage the workpiece or tool. If the diameter of the milling cutter is too large, it will 

damage the tool itself and the workpiece because the milling cutter cuts in the center and may collide at the base of the tool.

In order to extend the service life of the tool, the tool should be kept as far away from the hole or interrupted part of the workpiece as possible during end milling. When the 

face milling cutter passes through the middle of the hole in the workpiece, the tool mills along one side of the hole and counter-mills on the other side of the hole, which will 

cause a great impact on the insert. This can be avoided by bypassing holes and pockets when programming the tool path.

By choosing the appropriate milling cutter angle, size and feeding method, the tool can reduce the minimum vibration and tensile stress of the workpiece material, and know 

in which cases milling is more effective than drilling, and the manufacturer can process the workpiece efficiently and cost-effectively. The spaces are the delicate parts.