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Achieving Sustainability In Manufacturing

Achieving Sustainability In Manufacturing

The hype of the manufacturing world in recent years is centred on sustainability—of practices, of technology or of waste disposal—for a better future. But what exactly does ‘sustainable manufacturing’ mean, and how can a manufacturer achieve or engage in it? By Michelle Cheong

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Redefining Productivity: New Advances In Inserts Technology

Redefining Productivity: New Advances In Inserts Technology

Customers always look forward to procuring parts and devices from manufacturers that are reliable in providing quality products that achieve output that does minimal to affect the delivery schedule. Staffan Lundström, product management, parting & grooving, and Bimal Mazumdar, product manager, Sandvik Coromant, explain what it takes to achieve such a status.

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Sandvik Coromant: Corobore 826

Sandvik Coromant: Corobore 826

Sandvik Coromant has taken another step in the development of fine boring technology by introducing CoroBore 826, a groundbreaking high-precision (HP) coolant tool for trouble-free machining and close hole tolerances.

Machine stops caused by chip tangling around the tool or spindle are a common problem in fine boring. With the high-precision nozzle, CoroBore 826 HP directs the high-precision coolant jet to the cutting edge in order to efficiently control and break the chip. Chips are then easily evacuated from the hole. Combined with the user-friendly stepwise scale setting of the tool diameter provides the perfect tool for accurate fine boring.

CoroBore 826 HP is the ideal first choice fine boring tool for requirements in the range of 36–1260 mm (1.417–49.606 inch). It is optimised for process repeatability, hence ensuring excellent surface finish and close hole tolerances.

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Elements For Successful Face Milling

Elements For Successful Face Milling

Boost productivity in face milling operations with pivotal technologies. Contributed by Sandvik Coromant.

More manufacturers are faced with trying to boost the productivity of face milling operations and reduce component costs in a bid to achieve competitive gain and grow market share.

There are many notable trends in the component milling arena, particularly where batch sizes are above average and where there is a degree of component complexity that makes parts challenging to clamp. When clamping is more unstable, the application becomes prone to vibration.

Here, the typical tools used in larger volume production are double-sided inserts with many cutting edges that are able to positively impact overall productivity and cost per component. Such tools, however, are based on negative concepts that often produce a heavy cutting action, elevated cutting forces and higher energy consumption, along with greater tool wear and burr formation. As a result, in vibration-prone applications, these cutters struggle to meet the high performance levels demanded.

Single-sided insert concepts, although positive, are generally dismissed in higher batch applications due to their limited number of edges.

Positive Effect

It seems clear that a face mill with double-sided, multi-edge inserts that is capable of positiveeffect cutting would prove ideal. This demand is highlighted further as a result of another marked trend in milling strategies that is found particularly in sectors such as automotive – the shift away from fixed transfer lines towards universal, smaller machining centres that can better accommodate mixed production requirements.

While smaller, less powerful machines are a good choice from a production strategy perspective, they are not always suitable for the negative, heavy cutting concepts that these manufacturers traditionally deploy.

As a result of fierce global competition, seemingly eternal cost pressure is another factor that cannot be ignored at modern component machining facilities. However, in higher volume machining, even a small saving per component can equate to large cost reductions in term of overall production. As a result, manufacturing engineers look to optimise their processes on a constant basis, a strategy which includes close scrutiny of cutting tool selection.

Favourably Tilted

To help maximise yield as well as well as to satisfy the need to reduce component costs, new milling cutter innovations are pivotal. With this in mind, Sandvik Coromant has come up with a multi-edge cutter that can produce a positive, light cutting action in a host of different roughing to semi-finishing operations on steel and cast iron workpieces (ISO P and ISO K materials).

The CoroMill 745 offers a total of 14 true cutting edges offering higher depths of cut than comparable existing cutters. It has an unconventional insert inclination angle, which is designed to offer a large, positive angle on the main cutting edge, which in turn enhances chip formation and delivers smooth, soft sound and low cutting forces.

Although a visual inspection of the tool will reveal that the inserts are configured negatively, their combined effect is positive. This helps manufacturers take advantage of situations where productive yet light cutting is required, including where unstable set-ups or lower powered machines are deployed.

In essence, the tool’s positive cutting action mirrors that of a single-sided concept face mill, but instead features cutting edges on both sides of the insert to help lower piece part costs. All face milling operations up to 5.2 mm depth of cut are expected to benefit.

Green Light For Accelerated Automotive Turning

Green Light For Accelerated Automotive Turning

An interesting approach towards the external turning of steel parts in high volume offers opportunities for manufacturers in the automotive industry. By Håkan Ericksson, global product specialist at Sandvik Coromant

Manufacturing engineers in the automotive industry have tried almost everything to extract the last drops of productivity from their conventional turning processes. Although these processes are evolving by making small gains on an almost constant basis, a different approach looks set to help turning shops take a step forward.

With a different take on turning conventions, PrimeTurning from Sandvik Coromant offers opportunities for manufacturers tasked with the external turning of steel parts in high volumes. The methodology can not only address many of the common challenges faced by automotive original equipment manufacturers (OEMs) and suppliers, but also provide potential gains.

Turning Predominance

Steel turning dominates many automotive applications, including the production of transmission shafts and shift sleeves, and flange and post ends on engine crankshafts, for instance. Hub units, constant-velocity joint components and drive pinions are among further examples. In a market as notoriously competitive as automotive, all of these parts share a common requirement: To maximise productivity without compromising quality.

The question is how can this still be achieved? Turning is a mature process that has been edging forwards for a number of decades but without a major step-change of note. Sure enough, more rigid machines have been matched with ever-improving workholding and cutting tool solutions, but the methodology of turning itself has not evolved.

The upshot is that turning has become a bottleneck in comparison with many other manufacturing processes which have advanced at a faster rate.

Turning On Its Head

In contrast to conventional longitudinal turning, the new turning methodology allows the tool to enter the component at the chuck and removes material in the opposite direction. Turning “backwards” in this manner allows a small entering angle to be applied, which in turn can provide productivity gains.

Experienced operators are aware that small entry angles permit increased feeds, but in conventional turning are restricted to around 90 deg in order to reach the shoulder and avoid the long, curved chips that small entering angles characteristically generate. In contrast, the new process provides reach at the shoulder and allows for entry angles of 25-30 deg, with chip control and maintained tolerances.

Of course, some machine shops have already tried turning from chuck to part end with small entry angles, but the problem has always been chip control. With the new methodology, however, there are chip breakers, edge preparation and a machining strategy that can account for chip thickness and a gradual release of cutting forces when entering the workpiece. As a result, speed and feed rates can effectively be up to doubled.

The small entry angle and higher lead angle 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 unwanted effect of conventional longitudinal turning.

This is good news for automotive manufacturing engineers under pressure to reduce cycle times and cost per part in order to stay competitive. The methodology also has additional benefits to offer, such as reducing downtime through fewer set-ups. This is because the new process allows for all-directional turning, which means that turning conventionally from component end to chuck can be performed using the same tools. This is supported by newly developed inserts that have three edges/corners: one for longitudinal turning, one for facing and one for profiling.

Efficient Edge Utilisation

Conventional longitudinal turning uses the corner radius and a small part of the insert side to create the chip, whereas the new methodology uses just the side to create a thin and wide chip. For facing operations, conventional methods continue to rely on the corner radius, thus further increasing wear. In contrast, the new methodology uses the other side of the insert, delivering edge utilisation and longer tool life.

Traditional turning methods always use the corner radius when turning, which leads to concentrated heat, excessive wear and unfavourable chip forms that are difficult to break, while the new methodology generates the heat in a wider and different area so that heat can move away from the cutting zone. The chip is also straight and easier to form.

All-directional turning presents possibilities for automotive shops to perform existing operations in a more optimised manner. Tests show that the new turning process is typically best suited to short and compact components, although all-directional turning inserts mean that slender parts can also be processed (conventionally) using a tail stock. With specialised Coroturn inserts, feed rates up to 1.2 mm per revolution and depths of cut up to 4 mm can be achieved, depending on the application.

Turning Code Generator

To highlight the potential gains on offer to automotive manufacturers through a combination of the new methodology, specialised inserts and a new code generator. Numerical control code changes can be viewed as problematic to many machine shops. With the aim of simplifying adoption of the new process, the specially-developed code generator facilitates changing from conventional toolpath programs to the new methodology.

Furthermore, it helps to maximise output through the application of optimised parameters and variables, and ensures process security with suitably adjusted feed rate and entry radius data.

Turning Hubs

The new methodology is suitable for use on CNC turning centres and multi-tasking turn-mill machines, and early customer tests have yielded results. For instance, when turning a hub made from cast steel (SAE/AISI 1045) on a Gildemeister CTV 250 CNC turning centre, a machining company in Brazil was able to achieve significant benefits.

Using the same cutting speed (300 m per min), the adoption of the specialised inserts allowed feed rates to be increased from 0.25 mm per revolution to 0.4 mm per revolution, and depth of cut from 1.5 mm to 3 mm. The result was a 59 percent increase in productivity and 55 percent more tool life. With over 120,000 hubs a year being produced, the overall impact on profitability is expected to be considerable.

The new methodology will thus appeal to automotive OEMs and their tier 1, 2 and 3 suppliers that know their cutting data and its current limitations.

The specialised insert is designed for light roughing, finishing and profiling

As cutting is performed in the direction moving away from the shoulder, there is no danger of chip jamming.

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