“Typically PVD coatings or uncoated tools are used for Swiss-type turning operations,” says Ludeking. “These provide the sharpest cutting edges, thereby reducing forces on the small workpieces. Also, these tools have higher edge toughness that helps them withstand the high forces generated when cutting at low speeds often encountered in small diameter components. Because CVD coatings require somewhat larger edge-rounding (hones), they tend to generate higher cutting forces that are detrimental to small components. On the positive side, new CVD coating technology is enabling smaller hones, making them good choices for higher speed operations or very abrasive alloys,” he adds.

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There’s a general consensus that when it comes to designing tooling for Swiss-type turning, coolant through is preferable to flood coolant. Coolant through tools utilize high pressure (H.P.) for delivery.

“Swiss machines have three work holding devices in them if you don’t include the bar feed collets. The headstock collet, the guide bushing (which is what the stock feeds through during the cutting and is used for support), and the pickoff or sub-spindle collet which takes a parted-off work piece and can hold it for secondary operations on the sub spindle side of the machine.

“The H.P increases the tool life and reduces the need for intervention by the operator for chips wrapping on a part.

“One of the tasks of our department is to strengthen the material flow from ore and scrap to the manufacture of cemented carbide tools, which are the final products. Our solution was to establish a recycling technology and a recycling center in the U.S. [discussed below]. The Sumitomo Electric Group started recycling tungsten in the 1980s. At that time, a recycling process called the “zinc process” was used to recycle scrap into raw material powder while retaining its constituents. In 2011, Sumitomo Electric developed a new chemical process to recycle scrap into tungsten trioxide (WO3), making great strides in recycling. Today, the recycled volume is equivalent to the weight of the cemented carbide tools sold by the Sumitomo Electric Group in Japan. However, this does not necessarily mean that Sumitomo Electric products accounted for 100% of the collected scrap. Part of the scrap was exported as valuables or melted with steel scrap. Of the total scrap generated in Japan, an estimated 30% is returned to our group. As the first step, we hope to increase the percentage to about 50%. To this end, we must expand both the collection capacity and the processing capacity. In terms of achieving stable supply, we are studying the possibility of investing to acquire interests in mines in addition to promoting recycling,” said Okamori.

Japan depends on imports for most of its energy and mineral resources. At present, there are no mines in Japan that produce rare metals, including tungsten. For this reason, ensuring the stable supply of energy and mineral resources is one of most important national issues. Against this backdrop, the Ministry of Economy, Trade and Industry formulated the New National Energy Strategy in 2006. It mentioned the need to step up efforts to promote recycling of metallic mineral resources. The Guidelines for Securing Resources, which were established in 2008, set out a policy to support the acquisition of important resources, including rare metals. In the following year, the Strategy to Secure Rare Metals was published. In 2012, five minerals— neodymium, dysprosium, tantalum, cobalt and tungsten—were selected as priority minerals to be recycled. A national project is under way to secure these rare metals. Why are rare metals so important? Although they are consumed in small quantities, they are indispensable materials in the manufacture of LCD TVs, mobile phones and vehicles. In fact, they are essential in maintaining and strengthening the international competitiveness of Japan’s manufacturing industry. Notably, global demand for rare metals is expected to increase in the fields of nextgeneration vehicles, motors and storage batteries, which are expected to come into widespread use in the building of a low-carbon society. In terms of the use of tungsten, cemented carbide accounts for about 61% of the global market on average. In Japan, the percentage of cemented carbide is particularly high (about 76%).* Derived by mixing WC with cobalt (Co), cemented carbide achieves high hardness, high wear resistance, and high heat resistance. Cemented carbide tools, such as drills, and cemented carbide inserts for cutting tools have achieved high-speed machining and revolutionized the operation of manufacturing and machining sites. In Japan, the Sumitomo Electric Group has become one of the pioneering companies of this technology. Cemented carbide tools are crucial for many manufacturers. It is safe to say that these tools are the lifeline of manufacturing and machining. Tungsten is an essential material in the production of these tools.

“On the I.D, using coolant-through drills for instance, can gain you a 2x feedrate over a standard carbide drill or 3x to 4x a cobalt drill, while you can also increase your SFM for the tool,” he explains.

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To sum up, Laprade cites an old retail truism. “Swiss tooling is a very ‘get what you pay for’ type of product. When you’re trying to continuously ‘split tenths’ you want something that is high quality and more importantly, repeats each time a job is set up or when a tool is changed. A good tool or tooling system will eliminate the need for an operator to chase a tolerance because the tooling wasn’t intended for it or is poor quality,” notes Laprade.

Exsys Tool places its expertise with tooling for Swiss-type machines front and center. The company highlights its Decoflex tooling system for interchangeable tools.

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“At GenSwiss we recommend micro-thin PVD coatings that don’t change the edge conditions of the cutting tools when applied to them,” adds Scott Laprade, marketing manager, Genevieve Swiss Industries, Inc. (GenSwiss). “When working with small diameter parts you want the edges to remain as sharp as possible to prevent pressure build up which can lead to deflection of the work piece. Some coatings and processes deposit a ‘bead’ of coating on the edge of the insert which can round it off by up to a thousandth of an inch.”

Insert shape also plays a big role in Swiss-type turning “since we normally do not rough and finish turn parts. Parts that have undercuts, larger grooves, angles into smaller diameters, and other features like that, are studied to see if a different tool can provide the entire profile in one turn. If not then we have to look at segmenting the part into sections to process,” says Paoletta.

“Maximizing the envelope is crucial given the tooling requirement to complete a part versus space provided,” adds Jim Garfield, regional sales manager, at Horn USA. “Swiss type multi-function tools can reduce the number of tools/holders required as well as reduce cycle times. Quick-change Swiss holders can reduce downtime when changeover is necessary due to tool wear or new part set up. Repeatability of center height when changing insert/tools is of utmost importance,” he adds.

Cemented carbide scrap is classified into two main categories: solid hard scrap and powdery soft scrap. The former includes used or defective cutting tips, drills and dies/molds, while the latter refers to powder sludge generated during grinding and polishing at manufacturers of cemented carbide materials and cemented carbide tools. The sorting and collection of such scrap are crucial processes in the completion of a recycling system. When Sumitomo Electric started to recycle scrap in the 1980s, it also started to collect scrap. Recycling collection boxes are made available to customers, which use cemented carbide tools. The boxes, which are used to sort cemented carbide tools and other materials, are collected periodically. The company also accepts scrap from competitors’ products. It has also started collection by using a home delivery service. All the cemented carbide scrap collected is transported to the Igetalloy Scrap Center for sorting. The entire collection process is undertaken by Sumitomo Electric Tool Net, Inc., which sells cemented carbide tools. Shinji Nakao, General Manager of the Environment and Resources Sales Dept. of Sumitomo Electric Tool Net, has been engaged in the collection from the outset.

GenSwiss’ recently released its Ti-Loc SwissClamp System “for rotary tooling in Swiss machines … it can be used for milling and slitting operations that utilize ER collets for tool holding,” explains Laprade.

“In Swiss applications where the parts and work envelope are generally smaller, through coolant when and where available is always a better option than relying on flood coolant,” says Garfield.

Horn, among other cutting tool companies, has new offerings for the Swiss-type turning sector. “Although Horn has traditionally been oriented towards small part Swiss type machining, we have introduced new tooling dedicated to Swiss-type turning grooving and milling applications. A recent introduction to our existing 274 line was the System 274 ‘µ’ finish for micro turning, grooving and back turning. In addition, our Graf line of Swiss tooling offer numerous options for holding with round shank holders and height adjustable quick change holders for most Swiss type machines, i.e. Star, Miyano and Citizen,” says Garfield.

“When turning the O.D. of a part, H.P. coolant pays big dividends on gummy/hard materials or long cuts where stringy chips are a problem,” says Paoletta.

“Recycling of cemented carbide scrap is important partly because it is highly effective in terms of environmental conservation. The percentage of tungsten contained in ore is less than 1%. Meanwhile, the percentage of tungsten contained in cemented carbide tools is about 85%. From the viewpoint of refining efficiency, it is far more environmentally friendly to extract tungsten from the scrap of cemented carbide tools. It should also be noted that global tungsten reserves are estimated at about 3.2 million tons. Thus, the resource is likely to be depleted in the near future. Global competition for tungsten will intensify. We must further expand the scope of recycling to protect Japan’s manufacturing industry. While such efforts partly reflect our business strategy to encourage customers to use Sumitomo Electric products, we will publicize the importance of recycling through activities to foster motivation and raise awareness with the SDGs in mind,” said Nakao.

As Swiss-type turning edges towards the mainstream, cutting tool companies continue to provide a steady stream of appropriate tools. Such tools have to be able to function in the confined work envelope characteristic of Swiss-type machines.

* Source: Statistical Report 2013 published by the International Tungsten Industry Association (ITIA)

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When the question is about the best kind of coatings on Swiss-type turn tooling, there’s further consensus.

“Manufacturers have really paid attention to the growing market and needs of the Swiss turn industry, so there really is a lot available [that meets] the needs of the Swiss-type turn shops,” he continues. “Considerations in tooling must also be made in relation to the geometry of the part and a possible non-standard program format to create certain part features. Some Swiss machines are limited on stick tool stations. There are many new tools out there that combine several things like face, turn, groove for the O.D. or drill, bore, and thread for the I.D. By using these combinations we can free up tool stations allowing us to machine more complex or tooling intensive parts with the limited stations.”

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“Decoflex is a modular tooling system specifically designed for Swiss turning head stock machines…we have introduced a multi-headed collet chuck that will work in both directions of the spindle simultaneously,” says Scott Leitch, marketing manager with Exsys.

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The Japanese government has set the procurement of rare metals as a national project due to changes in the environment surrounding rare metals. From the latter half of the 20th century to date, the framework of the global economy has changed significantly due to the rise and development of emerging countries, including China. Global production and consumption have accelerated, resulting in the expansion of consumption of rare metals. Against this backdrop, there has been a rising tide of resource nationalism (the belief that the resources available in a country should be managed and developed by that country) among producing countries. Tungsten is no exception. Previously, Japan imported much of its tungsten from China, which accounted for more than 80% of the global production volume. Today, tungsten is a mineral subject to export control in China. The production volume in other countries, including Vietnam and Russia, is limited. It is evident that tungsten will be depleted in the near future. Under these circumstances, the Sumitomo Electric Group has embarked on the recycling of tungsten. This is a challenging project to free the company from dependence on imports and achieve a stable supply by recycling tungsten. The Administrative Dept. of the Advanced Materials Business Unit is responsible for procuring metallic materials for cutting tools, including tungsten. General Manager Yoshimitsu Okamori is one of the members who have led the efforts to recycle tungsten.

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The new Walter Cut G1011-P grooving tool from Walter USA, which can be used in Swiss-type turning, is internally cooled. “The G1011-P is designed so the coolant stream is released very close to the cutting edge, guaranteeing the best possible effect of the coolant, no matter what the supply pressure is,” says Kurt Ludeking, product manager of turning at Walter USA. “Compared to an external coolant supply, this ensures coolant at the cutting edge throughout the cut, especially important in deep, narrow grooves and parting operations

Rego-Fix Tool, meanwhile, recently expanded its retrofit reCool coolant through system. Previously matched with live tooling on CNC lathes, the system can be now be used with static toolholders on Swiss automatic machines.

“Most Swiss machines just use flood coolant [and have] a little stick out there shooting the oil where you’re cutting. That may or may not be an accurate way of getting [coolant] there. [The reCool system] brings the coolant in through the nut, and now you can go through your cutting tool, something that’s always been hard to do with a Swiss machine,” says David McHenry, engineering and technical manager at Rego-Fix Tool.

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“There are many tools that were designed with the Swiss machine in mind, due to the limited tooling space and stations,” says Douglas Paoletta, president and owner, Encompass Swiss Consulting in Richmond Heights, Ohio. “Iscar’s Pentacut insert, which is a five-sided indexable tool, is one. One of the first ‘back turning’ tools, and still one of the best, is the Kyocera ABS/ABW series tool. Kennametal has one of the best ‘quick change series’ tools called the KM Micro,” adds Paoletta, whose company offers on-site training for shops and manufacturers interested in Swiss-type machining.

“Coolant delivery can be the key to success and direct delivery via coolant nozzles built into the tools can have benefits of better chip control and cooling of the component and chips,” says Kevin Burton, product specialist at Sandvik Coromant in Mississauga, Ontario.

“Each of these devices can be ordered with special options that might pertain to the application being performed. Special ID tolerances, extended nose lengths, extended land surface, over gripping geometry, or special ID shapes are all things that can be modified on a guide bushing or pickoff collet,” says Scott Laprade, marketing manager, Genevieve Swiss Industries, Inc.

“PVD coatings are most common due to the reduced heat factor in small part machining—small contact diameter, lighter feeds and good cooling. The required sharper cutting edges also dictate that PVD be used,” echoes Burton.

Industry experts were also asked about grades and geometries for Swiss-type turning tools. “A grade specifically for use in Swiss-type turning is WSM21, a mono-layer PVD coating that is designed to withstand the low cutting speeds often encountered with small diameter components. Grades with thinner PVD coatings and sharp edges are generally best,” says Ludeking. “Although there aren’t any specific Swiss-turning geometries, those with aggressive chip control for light feed rates and depth-of-cut are often best for Swiss-type operations.”