Metal machining is a technological procedure of shaping a vast variety of metal alloys by milling machines. It can be achieved by usage of manual tools, hand tools, and dedicated machines (mills, lathe, manual, automatic, and CNC controlled).
The goal of metal machining is the production of a shape or part with specific parameters. The complexity of that process is related to the type of machined alloy. The higher its rigidity, the more specialized tools, and procedures are required. Still: the metal milling process has been well-known for ages. Parts made in that process are important elements of many machines.
Metal milling (CNC and automatic) - what is that process?
Metal milling is a process of machining blocks of metal alloy. It allows to form an element or part of the expected shape – usually with a routers: manual, or CNC controlled. Metal machining uses a high-speed spindle with a specialized cutting tool. It is able to remove small parts of metal blocks (in form of shavings and dust) to shape elements.
Metal milling is a form of shaving machining. During that process, the excess material is removed in the form of shavings. The machining tool itself has structured geometry and amount of blades. That process can be performed in many axes.
Thus creates a possibility to produce complex elements and parts with various shapes. Such features allow repetitive production of identical parts and elements. But still: time-consuming.
On the other hand: CNC milling improves the process. Allows fast production of a high quantity of repeatable parts with minimal tolerances. Usage of CNC machining can improve the speed and precision of production. And that can lead to quick manufacturing of high quantities of cost-efficient parts.
Despite these advantages, classic milling (sometimes called "automatic" or "manual”) is still
important. Especially in production of a single or small quantity of elements.
Metal milling always requires:
- selection of the right cutters for the type of metal alloy,
- selection of the right parameters from the milling process (e.g. speed, RPM), with the type of alloy in mind,
- the division into stages, e.g. initial milling, precise milling, finishing milling. Also: and adjustment of milling machine work for specification of each of them.
In the case of ordering CNC metal milling services the customer just needs information related to the ordered product: its specification and physical characteristics. A professional team of experienced CNC operators will select the right techniques of metal milling. And achieve the highest quality final product, along with client expectations.
Types of metal milling and machining
The process of milling metal can be divided based on kinematics (movement of the spindle) and construction (machined surfaces).
Metal milling can be described by its kinetics for:
- up-cut milling - direction of the cutter rotation is opposite to the direction of spindle movement. It is a very efficient form of milling, used in the initial stage of machining metal. It reduces unwanted vibration and speeds up the work, although for the lower quality of machined surfaces,
- climb milling - direction of the cutter rotation is in line with the spindle movement on the machined surface. That type of kinetics is used in precision milling due to higher precision and better quality of the surface. The disadvantages of that type of kinetics are higher vibrations.
Metal milling can be divided also by its technological aspects, related to machining many types of metal alloys. The technological classification of milling is:
- front milling – machining surfaces of the cutter (blade) are on the frontal and to some extent on the cylindrical part,
- cylindrical milling – machining surfaces of the cutter are on the cylindrical part of the cutter. Only that part is in contact with machined material,
- miter milling – utilizes special milling cutters (blades are spread on the surface of the whole tool). With the milling surface, they create an angle between 0 and 90 degrees.
Key parameters of different types of metal milling
Metal machining requires different parameters of work – as for automatic and numerically controlled (CNC) milling. It should be adjusted to the stage of machining (initial, precise) and type of the alloy.
Different types of metals require dedicated procedures of machining, and adjustment of key milling parameters, such as:
- milling depth – is defined as the depth of cut in every spindle pass,
- milling width – is defined as the width of cut every spindle in subsequent passes (e.g. overlapping of milled areas in each patch),
- milling speed – a very important parameter that has a strong impact on the milling time. An important element of that parameter is the rotational speed of the cutter. It is defined by the type of milling metal and chosen cutting tool while maintaining limits accepted for such process,
- feed velocity – it is the movement velocity of the spindle. The moving element of the milling machine can be the spindle (machined element remaining static), or the table itself (spindle remains static).
Each of the parameters should be selected and adjusted for the optimal utilization of the CNC
milling machine features and used cutters.
Traditional and numerical milling - what is CNC metal milling
Traditional metal milling utilizes manual and / or automatic mills. Such a process has been present in almost every industry for decades. For years such tools were used to produce many sorts of elements from metal, wood, POM, and many other materials.
The milling itself provides high efficiency and precision in shaping surfaces. Although its advantages, manual and automated milling, it is time consuming. That limits the production (especially: its quantity). Yes, such machining is perfect for one-off production and helps to keep the lowest tolerances and best fitment. But with a cost: more attention to detail makes that process less efficient and more expensive – due to the need to lease each movement of the spindle.
The real change in the milling of metal and other materials is related to the introduction of CNC: computer numerical control in the 50s. Such development decreases the time needed to lead the spindle and makes the whole process of milling much faster. Due to its automatic nature, the milling process is controlled by a computer and given instructions.
The disadvantage of that process is also pretty clear. Although the milling process itself can be sped up, the preparation for the work is time- consuming. Preparation of instruction for the CNC metal milling process is time consuming. On the other hand: the whole process, when programmed, is much faster than manual milling. That is why CNC metal milling is the most efficient over 100 elements.
A few words about us
At RADMOT, we can offer CNC milling services, CNC turning services as well as many additional services, including washing, aluminum anodizing, laser marking and assembly.
Contact us and tell us what you need. We have been providing CNC services for almost 40 years. Our quote is completely free. And if you are in doubt about which technology will work best for you, we are able to advise customers from many industries on machining and quickly determine the price of machining the parts you order - our expertise is at your disposal.