Turning is a mature machining process that has seemingly been around forever. However, those thinking that their process is rock-solid – tweaking and fine-tuning parameters to maximize output and profitability – need to think again. What if there was a new way of turning that questions established and preconceived ideas about this age-old process? The time has arrived to join the new turning revolution and breakthrough existing production barriers to revel in new-found productivity.

1. www.sandvik.coromant.com
Turning revolution – a surprising take on a mature process
By Håkan Ericksson, General Turning Product Manager, Sandvik Coromant
Turning is a mature machining process that has seemingly been around forever. However, those thinking that
their process is rock-solid – tweaking and fine-tuning parameters to maximize output and profitability – need to
think again. What if there was a new way of turning that questions established and preconceived ideas about
this age-old process? The time has arrived to join the new turning revolution and breakthrough existing
production barriers to revel in new-found productivity.
Throughout its long history, turning in the conventional direction – namely starting at the end of the workpiece and
working longitudinally towards the chuck – has prevailed. Although this technique has proved successful, as the process
has matured, ongoing advances in productivity and profitability have been increasingly difficult to achieve. Many are
bound by the limitations of traditional turning. For instance, while experienced operators are aware that factors such as
small entry angles permit increased feeds, they are restricted to around 90° in conventional turning in order to reach the
shoulder and avoid the long, curved chips that small entering angles characteristically provide.
In recent years, the advent of globalization has led to a trading environment for machined parts that is becoming
increasingly challenging. Manufacturers need to reduce their costs in order to compete. Production engineers are under
pressure to increase cutting parameters and/or reduce tool set-ups, but find that turning is slowing them down. In many
cases, it has become a bottleneck operation.
Turning in a new direction
Machine shops around the world have only known one way of turning – and that approach has been around for decades,
arguably spanning back not just one but two generations. But what if there was something that could deliver genuine
competitive gain? To make such a leap, the very principles of conventional turning would have to be challenged.
This is the exact thinking applied by Sandvik Coromant in its development of PrimeTurning™, a revolutionary new
process that has to be seen to be believed.
The company’s engineers began by investigating the potential for longitudinal turning to start at the chuck end and cut
material ‘backwards’ as the tool traverses towards the end of the component. Although some machine shops have
already tried such a method, the problem has always been chip control.
In PrimeTurning, Sandvik Coromant has succeeded in developing a solution that not only overcomes the chip control
issue, but provides multiple benefits. For instance, it allows a small entering angle to be applied, which in turn provides
considerable productivity gains. In fact, the potential exists to effectively double feed rates and increase speed in
comparison with conventional turning. This is because small entering angles or higher lead angles create thinner, wider
chips that spread the load and heat away from the nose radius, resulting in increased cutting data and/or tool life.
Furthermore, as cutting is performed in the direction moving away from the shoulder, there is no danger of chip jamming,
a common effect of conventional longitudinal turning.
Multi-directional benefits
If this sounds appealing, how about if the concept could be taken a step further, allowing for ‘all-directional’ turning? This
would mean, instead of having new inserts dedicated to ‘backwards’ turning, these tools could also perform conventional
direction turning, as well as facing and profiling. One tool for all directions. PrimeTurning offers precisely that,
representing a step-change for the future of turning and delivering advantages such as better machine utilization (due to
less set-up time), substantially longer tool life, fewer production stops, less tool changes and reduced tool inventory.
Although the process is relevant for the general turning arena, there are certain applications and machining
environments where it will act as a significant gain provider. For instance, it will certainly suit the turning of short and
compact components, but still be capable of machining long, slender parts (using a tailstock).
Turning enters a new era

2. With PrimeTurning, a combination of advanced strategies, tooling and programming codes provides perfect reach at the
shoulder and allows for entry angles of 25-30°. The result is significantly enhanced metal removal rates, excellent chip
control and well-maintained tolerances. Depending on the current set-up, PrimeTurning can boost productivity to levels
that are presently unattainable. Any machine shop not maximizing its productivity is not as competitive as it could be. If
turning is a bottleneck operation, for example, the company is suffering a restriction on the number of components
produced per run. Similarly, if machine utilization is low, the potential to make more components in less time is being
missed. PrimeTurning can help turn these limitations into opportunities and offer companies a quick return on
investment.
Suitable for use on CNC turning centers and multi-tasking turn-mill machines, this fresh take on a mature process also
offers the flexibility to turn in all directions for extraordinary productivity. A single insert is able to perform longitudinal
turning (in both directions), facing and profiling. Temperature control is also improved because heat is generated in a
wider and different area to conventional inserts. This means that heat can more easily move away from the cutting zone.
The chip is also straight and easier to form.
Parts made from ISO P (steel), S (heat-resistant super alloys and titanium) and M (stainless steel) materials are set to
benefit initially, with expansion to more materials in the near future. Additionally, the process will evolve into internal
turning operations, providing an indication that this trailblazing development will continue to drive the turning revolution
forwards.
First step-change in decades
PrimeTurning represents the first significant step-change in turning strategy for many decades. Of course, it would be
remiss to state that this avant-garde methodology is suitable for all applications – the existing Sandvik Coromant offer for
turning will continue to provide optimized tools and tooling systems where PrimeTurning is not the most appropriate
solution. For instance, for longitudinal and face turning in steel workpieces, CoroTurn®
300 can offer high component
quality, increased handling efficiency and long tool life. The tool integrates the latest advances in iLock™, Inveio™ and
high-precision coolant technology to take steel turning into the future using an insert with eight, 80° cutting edges. More
edges also mean fewer inserts, which in turn means reduced inventory.
So which type of manufacturer is likely to benefit the most from PrimeTurning? Any company performing conventional
external turning in large batches – automotive original equipment manufacturers (OEMs) and tier one, two and three
suppliers for example – as well as machine shops working in industries such as aerospace, where several set-ups and
tool changes are often required. Essentially any company seeking a boost in productivity; companies that know their
cutting data and its current limitations; and companies open to embracing new technologies and industry trends.
Turning will never be the same
Just when machine shop managers, engineers and operators thought they had gleaned every last bit from their
production, all-directional turning has arrived to deliver even greater recompenses. The tools, methodology and software
provide significantly greater metal removal rates, excellent chip control and achievable tolerances. Ultimately, those
wishing to increase cutting data and profits, should simply join the turning revolution.
For further information visit www.sandvik.coromant.com/primeturning
[sidebar]The history of turning
Records of an early industrial lathe exist from 1772, when a horizontal boring machine was installed at the Royal Arsenal
in Woolwich, London. It was horse-powered and featured a workpiece that turned, rather than the tool, making it
technically a lathe. This period of the industrial revolution also witnessed the arrival of mechanized power via water
wheels or steam engines. Between the late 19th and mid-20th centuries, electric motors started to take over as the main
power source. Then, beginning in the 1950s, servomechanisms were applied to the control of lathes, which were
subsequently coupled with computers to yield computer numerical control (CNC).

3. Video link: https://www.youtube.com/watch?v=nCYihCotzHw
Photos:
CoroTurn Prime A-type features three 35° corners and is
designed for light roughing, finishing and profiling
CoroTurn Prime B-type with its ultra-strong corners
is designed specifically for rough machining
Image 3: CoroTurn Prime in action - as cutting is performed
in the direction moving away from the shoulder, there is no
danger of chip jamming.
Image 4: The new PrimeTurning methodology and
CoroTurn tools from Sandvik Coromant enable
turning in all directions for the first time