Radial arm drill: what is this machine used for?

One of the most versatile machine tools in the metalworking industry is the radial arm drill or radial drill. There are many types of drilling machine on the market, but all of them, including the radial, perform, among other things, the same function: machining workpieces by creating holes through metal cutting.

What is a radial arm drill?

The radial arm drill is also called a radial drill and is used for machining workpieces through metal cutting (which creates holes) with a multi-edged tool called a drill bit. The radial arm drill is said to be one of the most versatile machines because it can work on a variety of materials: metals, wood and glass.

All the operator has to do to work the different types of material is change the drill bit. That is, use one that is suited to the material being worked.

What does a radial arm drill do?

A radial arm drill is not limited to machining workpieces by drilling; other types of work can also be carried out, such as roughing (removing rough spots) and countersinking (smoothing out recesses). This type of drilling machine, regarded as a pillar type, has the advantage of being very fast and can cover quite large working areas: this depends on the length of its arm.

Features and parts

Radial arm drills are characterised by a head with a spindle that can slide along the arm on which it is mounted. The arm, likewise, can move vertically and rotate along the column of the machine through angles of up to 360°. On some radial arm drills, the arm can move around a horizontal axis, which makes it possible to drill holes in all directions without having to reposition the workpiece being machined.

A radial arm drill consists of a horizontal base on which a fixed table (tool or workpiece holder) is placed. The table has a series of fixtures or guides that make it possible to secure the workpiece to be worked on its surface so that it does not move while the machine is running.

On the base there is a cylindrical column on which the arm sits, moving up and down. The arm is moved by a worm drive located at the top of the drill's column. In addition, the arm has a carriage that carries the tool head, which provides the translation, rotation and vertical displacement movements of the spindle, and it is in the spindle that the drill chuck is housed.

Advantages of the radial arm drill

As we have already mentioned, this type of machine is very fast and can cover large working areas. This varies depending on the length of its arm; however, the size of the arm does not prevent the drill from performing one of the functions that make it one of the most sought-after tools: rotation of up to 360°.

In addition, with this type of drilling machine it is possible to machine not only workpieces of different materials, but also of different sizes. This is because the arm of the machine makes a rotating movement outside the working area; this is why large workpieces can be placed on the worktable (with the help of cranes) to be machined.

Another advantage of this drill is its design. Some radial arm drills are floor-mounted, but it is more common to find them fixed to worktables, which makes it much easier to place the workpieces on the surface where the drill is located, without having to reposition or rotate them, since the drill arm extends to cover large surfaces (as far as the length of the drill's own arm allows).

Without doubt, one of the reasons machining workshops include these machine tools on their premises is the saving in time and personnel. This is because it is increasingly common to find a radial arm drill that runs on Computer Numerical Control, or CNC. Thanks to this technology, the process is automatic and only one operator is needed to place the workpiece to be machined on the worktable and start the drill. The great majority of CNC radial arm drills use four work stations and can change tools automatically, so several workpieces can be worked simultaneously.

For a drilling machine to run automatically, all that is needed is to design a part using CAD design software and then process the data in the CAM software, which will tell the machine tool what it has to do.