Horizontal milling is the art of efficient production

Posted on Jul 27, 2020

Horizontal milling is the art of efficient production

Horizontal milling and milling is a machining process using cutting tools to remove material by sliding the tool heads into the workpiece. This can be done by changing the direction in one or more axes, cutting tool head speed and pressure. Milling covers many different operations and machines, ranging from small individual workpieces to large, heavy gang milling operations. Milling is one of the most widely used processes for machining non-standard parts with exact tolerances.

Milling can be done using a wide range of machine tools. The milling machine was often the original class of milling machines. After the introduction of computer numerical control (CNC) in the 1960s, milling machines turned into machining centers: milling machines enriched with automatic tool changers, tool magazines or carousels, CNC capabilities, cooling systems and housings. Milling centers are generally classified as vertical machining centers (VMC) or horizontal machining centers (HMC).


Multi-Task Machines

Integration of milling with the turning environment and vice versa began with live tooling for lathes and occasional use of milling cutters for turning operations. This led to the creation of a new class of machine tools, multi-task machines (MTM) that were designed specifically to facilitate milling and turning within the same work surface.



Milling is a cutting process in which the cutter removes material from the surface of the workpiece. The cutter is a rotary cutting tool, often with many cutting points. Unlike drilling, when the tool is moved along the axis of rotation, the milling cutter is usually moved perpendicular to its axis, so that cutting takes place around the perimeter of the milling cutter. When the cutter enters the workpiece, the cutting edges (grooves or teeth) of the tool repeatedly cut into the material and leave it, shaving the shavings (chips) from the workpiece with each pass. Cutting consists in shear deformation; the material is pushed from the workpiece into small lumps that hang down to a greater or lesser degree (depending on the material), forming chips. This makes cutting metal slightly different (mechanically) from cutting soft materials with a blade.

The milling process removes the material by making many separate, small cuts. This is done by using a knife with many teeth, rotating the knife at high speed or slowly moving the material through the knife; most often it is a combination of these three approaches. The speeds and feed used are varied to suit the combination of variables. The speed at which a piece slides through the knife is called feed speed or simply feed; most often the length of the material is measured per full turn of the tool.


Two Major Classes Of Milling Process

In face milling, cutting action occurs primarily at the end corners of the cutter. Face milling is used to cut flat surfaces (surfaces) to the workpiece or to cut flat bottom cavities. In circumferential milling, cutting action occurs primarily on the circumference of the milling cutter, so that the cross-section of the milled surface ultimately takes the shape of a milling cutter. In this case, the knife blades can be regarded as collecting material from the workpiece. Circumferential milling is well suited for cutting deep grooves, threads and gear teeth.

Read More: Horizontal Milling Machines Basics


Comparison Of Horizontal And Vertical Mills

So what are the comparisons / differences between horizontal and vertical milling? The task performed by both types of machines is basically the same, but the production process to perform the task is different. The main difference is the orientation of the spindle. There are advantages and disadvantages to both machining types, and it’s crucial to note milling functions can differ. Here is an overview of horizontal vs vertical mills.

Read More: What are the pros and cons of Horizontal Milling Centers?


Vertical Milling Machine

A vertical milling machine is the most commonly used type and has a vertically oriented cutting head or spindle that holds and rotates the cutting tool relative to the workpiece. Because the cutting head is mounted in a vertical orientation, other parts of the machine will move along one or more axes to move the material in the right position for proper milling. The mandrel moves up and down, removing material by pressing on the workpiece.

Vertical mills are ideal for unilateral projects, such as working with large metal plates and sinking matrices. There are basically two types of vertical milling machines: bed milling machines and turret milling machines - they work slightly differently from each other and offer unique advantages.

Turret mill: Here the table and the spindle can move perpendicularly and parallel to the axis. A revolver mill is very versatile, considering how it can manipulate the position of the material in both directions. In fact, most production invests in a revolver mill due to its ability to perform a wide selection of milling operations. Note that the biaxial movement supports smaller projects.

On the other hand, the bed mill: the bed mill moves the material perpendicular to the axis. With this milling machine, the spindle is attached to the vertical axis and can move up or down as needed. Movement of the spindle in combination with the horizontal movement of the table allows milling of various depths and shapes. This mill is perfect for projects that require large, heavy components compared to tower mills.

The best features of vertical milling machines

1). Popularity: these machines make up the majority of milling machines in the country. They are usually more affordable compared to horizontal mills, making them a smart investment that pays off ten times. Due to the low initial cost, production cost savings will be passed on to customers.

2). Ease of use: the construction of vertical mills provides operators with better visibility during work. This gives the operator (s) a better chance to easily detect and remove potential problems when milling begins. In addition, programming is easy thanks to user-friendly CNC controls. Therefore, operators will not waste time configuring and programming; instead, they will focus on ensuring that the project specifications meet the highest standards. Now, no matter what, milling machines should only be operated by experts with experience to safely complete the project.

3). Production benefits: The visibility provided by the vertical mills is excellent for finishing large sheets. Given the ease of use of the machine, it is better suited to less complex tasks requiring small amounts. This machine is ideal for fast milling work.


Horizontal Milling Machine

This machine has a similar construction in which a spindle with a rotary cutting tool removes material by pressing against the workpiece. Horizontal mills differ from vertical milling devices in different ways. An important difference between these two millers is the spindle orientation. Vertical milling machines have a vertical orientation of the spindle. As for horizontal mills, the spindle has a horizontal orientation. Simply put, a horizontal milling machine mounts the cutting head on a horizontally oriented spindle capable of selectively removing material from the workpiece.

In addition, horizontal mills are equipped with various cutting tools compared to vertical mills. While vertical mills have thin and long vertical cutting tools, while horizontal mills have thicker and shorter cutting tools. Compared to vertical milling machines, horizontal milling machines are able to make heavier and deeper cuts. Thanks to this, many manufacturing companies use them to cut grooves or grooves in workpieces. They can also perform milling operations when set at different angles.

Read More: Are CNC Horizontal Mills always the better choice?


The Best Features Of Horizontal Mills, Milling Machine, CNC Machine

1). Chip evacuation: Due to the position of the horizontal mills, when the cut is in progress, gravity will help in removing the chips. This will translate into end products with cleaner surfaces that will later require less production or production.

2). Solid construction: horizontal mills are heavier and can handle larger productions. Machine parts are built to last longer. Their rigid construction means that the machine vibrates less, bends less and runs smoother than vertical mills

3). Productivity: The integrated pallet changer and 4th axis massively extrapolate the performance of these machines, which is ideal for large volumes and complex loads.

Although they have similarities, horizontal mills are better suited for more complex designs than vertical mills. These machines will perform the tasks much faster, although this may require a significant increase in financial resources.


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