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All you need to know about radial heads

Feb 10, 2021 11:48:30 AM

The radial heads that can be fitted on transfer systems for tubes and bars are numerically controlled tool holders capable of considerably increasing the capability of the system and make feasible a wide variety of parts.

These heads use application-specific customized tool holders that can move the tool in a radial direction, in addition to rotating around the workpiece and moving parallel to its axis. All the three movements are interpolated and controlled by the CNC.

The movements can be easily programmed thru’ an intuitive human-machine interface.

Appropriate tools can be used to make internal and external profiles, such as threading, turning, boring, 3D turning, etc. to finish the component eliminating the need for secondary operations on other machines.


External and internal threading operation with CNC radial heads on a vertical rotary transferPair of CNC heads on EM80 transfer system used for cutting internal and external threads on tube.


Why use a radial head?

Thanks to the radial movement of this axis interpolated with other movements, these devices can reduce the tooling cost considerably because the use of profiled milling cutters or special tools are not required, in addition to reducing cycle and tool change times.

A radial head can perform all the common chip removal operations that are generally carried out on parallel lathes, such as internal or external turning, grooving, boring, chamfering, 3D turning, threading and facing.

The possibility of carrying out all these operations with the rotating tool and a fixed workpiece (instead of a fixed tool and a rotating workpiece as is the case of a lathe) means being able to reduce vibrations and improve machining precision, in addition to assuring high productivity thanks to the automation typical of a transfer system.

All these machining operations allow a wide variety of parts to be manufactured (such as shafts, fittings and couplings, bushes, threaded tubes, and so forth.). This versatility, coupled with the high productivity typical of a transfer solution, makes it an ideal solution to meet the most demanding production standards in terms of quality and parts per hour. The solution is ideal for sectors like automotive, household appliances, heating, plant engineering, that have medium-large production batches and have to work in a very strong competition environment.

Find out how to choose the right transfer system for tubes and bars.


Parts made from solid bar by chip removal on CNC transfer systemSome parts made from solid bar with a BLM GROUP EM80 transfer system.


Why use radial heads to thread tubes and bars?

Tube and bars can be threaded on a transfer system in two different ways: rigid and single point.

In the case of rigid threading, which does not require the use of the radial head, the cutting head is provided with a holder that houses an insert with an inverse profile of the threading to be cut. This type of solution is very fast because several threads are cut at once.

Single point threading, on the other hand, uses a single insert, its tip with an inverse profile of the thread throat. Radial heads can be used to manage the axial and radial movement of the tool to cut cylindrical or conical threads in a multi-pass operation, ensuring a higher thread quality compared to the first case in terms of surface finish. Such a tool insert can also be used for some other types of turning operation.


Tubular component with external and internal threading, made with a BLM GROUP EM80 transfer systemTubular component with external and internal threading, made with a BLM GROUP EM80 transfer system.


In what types of applications can radial heads be used?

Radial heads on transfer systems can be used to make parts for the most varied applications.

Radial heads are particularly useful in the manufacture of connectors used in white goods like household appliances, boilers and heaters.

In the hydraulic, oil and plant engineering sectors, CNC heads are used to manufacture fittings and other joining elements between pipes.

In the furniture sector, they are used for making different type of knobs or mechanical components for furniture and cabinets of various types.

In the automotive sector, they are used to manufacture cylindrical components such as engine parts or other vehicle systems components.





How can radial heads be fitted on a standard EM80?

EM80 is the BLM GROUP transfer system for cutting and end-machining on tubes and bars from 10 to 80 millimetres in diameter.

The fully automatic loading system feeds the system with tubes or solid bars up to 12.5 metres long. The system is capable of producing finished components up to 600 mm length by cutting and end-machining operations.

The EM80 has three processing stations. On the first station, the programmed length of the tube or bar is fed into the cutting clamps and this simultaneously expels the finished component. The second and third station can be used for any kind of machining operation and can be equipped with rotary tools, radial heads, facing tools or drills for drilling or centring. All stations work in parallel on successive parts, thus optimizing productivity.

EM80 transfer machining stations with cutting, radial milling and rotary toolsEM80 has three machining stations that can be equipped with cutting systems, radial heads, rotary tools and radial milling and drilling systems.


EM80 can be equipped with up to four radial heads, two on each side of the workpiece. In this way, either two different operations can be carried out on each station or the same operation can be split across the two stations equipped with these devices; for example, rough machining on station two and final machining on station three.



How can jobs with radial heads be programmed?

Using radial heads on EM80 is extremely simple. They are programmed directly from the human-machine interface and the knowledge of the ISO language is not required.

The machine receives the machining parameters from the operator by means of an intuitive, user-friendly touchscreen interface. The system’s post processor automatically translates the parameters set by the operator into ISO language and sends the work cycle to the CNC to start production.

In this way, in addition to guaranteeing high productivity standards, EM80 speeds up production changeovers and responds flexibly to the needs of its users.

An EM80 transfer system equipped even with multiple radial heads offers complete production process automation thru’ a simple operator interface. In this way, higher standards of productivity and quality of the parts produced, compared to the common CNC lathes, can be manufactured even with operators with no ISO language expertise. Thus, EM80 beats the traditional lathes even on smaller batches when a certain degree of flexibility in production planning must be guaranteed.