Milling machines are versatile machine tools that can machine planes, grooves, various curved surfaces, gears, and more. To enhance your understanding of milling machines, this article will introduce their classification and the differences between them and other machine tools. If you are interested in milling machines, please continue reading.
I. How to classify milling machines according to their uses
Milling cutters come in several commonly used types based on their applications:
① Cylindrical end mills: Used for machining planes on horizontal milling machines. The cutting teeth are distributed on the circumference of the end mill, and are divided into two types according to tooth shape: straight teeth and helical teeth. They are also divided into two types according to the number of teeth: coarse teeth and fine teeth. Helical coarse tooth end mills have fewer teeth, higher tooth strength, and larger chip space, and are suitable for roughing; fine tooth end mills are suitable for finishing.
② Face milling cutter: Used on vertical milling machines, end milling machines, or gantry milling machines for machining flat surfaces. It has cutting teeth on both the end face and the circumference, and is available in coarse and fine teeth. Its structure includes three types: integral, insert, and indexable.
③ End mills: Used for machining grooves and stepped surfaces, etc. The cutting teeth are on the circumference and end face, and cannot be fed axially during operation. When the end mill has end teeth that pass through the center, it can be fed axially (usually, double-edged end mills are also called "keyway cutters" and can be fed axially).
④ Three-sided milling cutter: Used for machining various grooves and stepped surfaces, with cutting teeth on both sides and the circumference.
⑤ Angle end mills: used for milling grooves at a certain angle, there are two types: single angle and double angle end mills.
⑥ Saw blade end mills: Used for machining deep grooves and cutting off workpieces, they have numerous cutting teeth on their circumference. To reduce friction during milling, the cutting teeth have a secondary cutting edge angle of 15' to 1° on both sides. In addition, there are keyway end mills, dovetail end mills, T-slot end mills, and various form end mills, etc.
II. Differences between milling machines and other machine tools
1. The difference between milling machines and planers
Milling machine: A machine tool that uses a milling cutter to mill workpieces. Besides milling planes, grooves, gear teeth, threads, and splined shafts, milling machines can also process relatively complex profiles. They are more efficient than planers and are widely used in mechanical manufacturing and repair departments. Planer: A linear motion machine tool that uses a planing cutter to plan the planes, grooves, or shaped surfaces of a workpiece. Planing requires simpler cutting tools, but has lower productivity (except for machining long and narrow planes). Therefore, it is mainly used for single-piece, small-batch production and machine repair shops, and is often replaced by milling machines in mass production. Based on structure and performance, planers are mainly divided into shaper planers, gantry planers, single-arm planers, and specialized planers (such as edge planers for planing the edges of large steel plates, and die planers for planing punches and complex-shaped workpieces).
A bullhead planer gets its name from the bull's head shape of its ram and tool post. The planing tool is mounted on the tool post of the ram and moves longitudinally back and forth. It is mainly used for cutting various planes and grooves. A gantry planer gets its name from its gantry-like frame structure consisting of a top beam and a column. The worktable carries the workpiece and moves linearly back and forth through the gantry frame. It is mainly used for machining large planes (especially long and narrow planes), as well as for machining grooves or machining several small and medium-sized parts simultaneously. Large gantry planers often come with milling heads and grinding heads, allowing the workpiece to be planed, milled, and ground in a single setup. A single-arm planer has a single column and cantilever. The worktable moves longitudinally back and forth along the bed guide rails. It is mainly used for machining workpieces that are wide but do not need to be machined across their entire width.
A planer is a machine that moves in a reciprocating linear motion by a tool or workpiece, or an intermittent feed motion perpendicular to the main motion by the workpiece and tool. Commonly used planers include: shaper, gantry planer, and single-arm planer.
2. The difference between drilling machines and milling machines
A drilling machine is a machine tool that primarily uses a drill bit to machine holes in a workpiece. Typically, the rotation of the drill bit is the main motion, and the axial movement of the drill bit is the feed motion. Drilling machines have a simple structure, relatively low machining accuracy, and can drill through holes and blind holes. By changing special tools, they can also perform reaming, counterboring, boring, or tapping operations. A milling machine is a machine tool that uses a milling cutter to mill workpieces.
3. The difference between boring machines and milling machines
Boring machines and milling machines have similar working principles and properties. The rotation of the cutting tool is the main motion, and the movement of the workpiece is the feed motion.
Boring machines are often used to machine long through holes, large-diameter stepped holes, and holes at different locations on large box-shaped parts. Because the boring head and boring bar of a boring machine have high rigidity, the straightness, cylindricity, and positional accuracy of the machined holes are all very high.
Milling machines can also perform boring, but their machining range is smaller and their precision is lower. Milling machines are mostly used for machining planes, shaped surfaces, grooves, etc.
Radial drills are highly efficient hole-making machine tools because their spindles can move rapidly and arbitrarily within the machining range while the workpiece remains stationary. Therefore, they are highly efficient at machining holes and threaded holes in different locations on large box-shaped parts.
