Stefan Steenstrup has been appointed the new President of global cutting tool manufacturer Dormer Pramet. Stefan, previously the company’s Global Sales Director, takes over from Fabrizio Resmini, who retires as of 1 January 2017.

Having worked for the Sandvik Group for the last 20 years, Stefan has held various senior positions after initially joining Dormer as technical specialist. In 2007, he became managing director of Dormer Italy, before moving into the company’s global management team.

Stefan, who speaks six different languages, was previously director of Business Development at Dormer Pramet following the merger of Dormer and Pramet Tools in 2014, becoming Global Sales Director a year later.

Originally from Denmark, Stefan, aged 46, will continue to be based in Milan, Italy.

He said: “As President of Dormer Pramet my work will initially be focused on continuity; continuity of our business model of being ‘Simply Reliable,’ continuity in delivering on key projects and continuity in driving us to our goals.

“I am excited to start this new challenge and I look forward to working with our customers, partners and colleagues around the world to achieve our ambitious growth targets.”

Stefan’s appointment marks the end of more than 30 years association with the company for Fabrizio Resmini, who started his career as managing director of SKF and Dormer in Italy. He became managing director of Dormer Tools Italy, holding the role for several years, before being appointed President of Dormer Group in 2001.

Fabrizio led Dormer’s merger with indexable carbide tooling specialist Pramet three years ago, and has guided the development of the new company within the industry as Dormer Pramet President.

Stefan added: “Fabrizio’s energy and contributions will be greatly missed. We wish him a happy and healthy retirement. Our success in recent years is a direct result of Fabrizio’s leadership and he leaves us a strong company, ready to take on the future.”

Pramet’s range of turning tools for stainless steel has been further extended with the launch of a new chip breaker and wiper inserts.

The NMR chip breaker provides a reliable option for longitudinal and face turning with high stock removal in medium and roughing operations.

This new geometry further enhances Pramet’s range of double-sided chip breakers for all turning stainless steel applications, which already includes NM for medium turning and NF for finishing to medium turning.

NMR’s positive geometry offers increased reliability through its strong cutting edge, which features a protective peripheral land. It is ideal for heavy machining and less stable conditions, with higher metal removal rates and predictable insert behavior providing increased tool life and productivity.

The NMR chip breaker is available for many types of Pramet inserts, including CNMG, DNMG, SNMG and TNMG.

Meanwhile, Pramet has also launched a new range of wiper inserts for turning.

Compared with standard inserts, the W-FM and W-NM wipers promote increased productivity by supporting higher feeds, as well as high quality machined surface, due to its new wiper edge.

In straight turning and facing operations, the smoothing effect of the wiper results in improved quality of surface roughness. If used properly, it can prevent the need for additional grinding operations, saving further costs.

Single-sided positive inserts with the W-FM positive geometry are suited to machining stainless steel and steels. The double-sided negative inserts with the W-NM highly positive geometry are ideal for machining stainless steel and low carbon steels.

Both feature a positive front land which further promotes smooth machining.

Designed primarily for high metal removal operations, the Penta HF is suitable for machining a wide variety of materials, including corrosion-resistant steels, difficult-to-machine steels and heat-treated steels.

The cutter features a 19° entering angle, enabling a maximum feed per tooth of 3mm. By supporting faster feed rates, machining time is reduced. In addition, a special surface finish promotes increased corrosion resistance, as well as reduced wear and friction resistance.

With its economical five cutting edge inserts design, the assortment is suitable for roughing to semi-finishing applications. Penta HF also supports internal coolant for deep milling and helical applications.

A wide range of diameters from 32 – 100mm, as well as a choice of shank and bore styles, offers a number of options for the user.

In a recent case-study in North America, the Penta HF cutter with PDMW inserts was able to machine an entire component of structural steel without stopping to index the inserts. This compared to a competitor’s insert, which needed to be indexed three times to complete the same application, provided a significant saving on machine downtime.

Pramet’s all-rounder is simply versatile

The universal 90° cutter features Pramet’s ‘AD’ program of indexable inserts, including the ADMX07, ADMX11 and ADMX16. All offer improved stability in a wide range of applications, even under unfavourable cutting conditions.

Combining solid performance with the ability to support multiple materials and heavy machining, the Force AD assortment is an ideal option for numerous operations, including ramping, helical interpolation and plunging.

Pramet’s Force AD line is suitable for use in a wide variety of materials, including steel, stainless steel, cast iron, titanium and nickel, and in some cases hardened steels, copper and aluminium.

A durable and versatile milling cutter with a wide range of diameters available, from 10 – 175mm, the assortment provides reliable clamping of the inserts, particularly within the helical range. In addition, its specially grooved body promotes fast and efficient chip removal.

Both these features combine to give a more accurate cutting process and excellent operating safety with high stability during machining.

Meanwhile, the Force AD line offers a variety of insert styles, with geometries for aluminium and high feed applications recently added to the assortment.

A positive geometry – with a rake angle of 25° – allows for a reduction in cutting forces, offering good productivity, lower machine power consumption and longer tool life.

Its cutting edge shape has been optimised to provide higher impact resistance and smooth machining. This, in turn, promotes a better work piece surface finish.

Compatible with a wide range of cutter bodies, internal coolant supply is supported across the entire range.

Stainless steel is a vitally important material for many industries around the world. Even though it was created more than 100 years ago, use of the material has increased significantly since the turn of the 21^st century.

Ricky Payling, application specialist at Dormer Pramet, outlines the growth of stainless steel, how the cutting tool industry has evolved to machine the material, as well as providing a summary of some of its most common grades.

According to the International Stainless Steel Forum (ISSF) the global demand for stainless steel products has nearly doubled in the last 20 years, and continues to grow five per cent each year.

In 2014, almost 42 million metric tons of stainless steel was produced worldwide – a 70 per cent increase from 2005 (24 million metric tons). This growth is predominantly achieved by an increase in China, where production has grown from a 13 per cent share of global output in 2005 to more than 52 per cent in 2014.

This rapid development is not only to meet worldwide demand, but also to support increased use within China, where stainless steel is consumed in household metal products, building materials and machinery.

Stainless steels’ anti-corrosive qualities make it perfect for use in a huge range of environments and components, such as aerospace, general engineering, consumer, oil and gas, medical and marine industries.

Its versatility is reflected by the fact that there are more than 150 different grades. Common stainless steels include ferritic, martensitic, austenitic, super-austenitic and duplex. More details of which are covered below.

The main alloying element is Chromium, which forms an ultra-thin oxide film on the surface. As a general rule, resistance to corrosion and oxidation increases in line with Chromium content. Other alloying elements, such as Nickel and Molybdenum, can be added to change the structure, increase corrosion resistance and improve strength.

This increase in production and consumption has coincided with advancements and new developments within the cutting tool industry. Due to the difficult process of machining stainless steel, manufacturers have invested a huge amount of time and resources in finding new ways to try to combat the numerous application challenges.

Recent introductions include changes to the cutting tool design, new geometries, improved coolant and developing stronger coatings to improve performance and tool life.

Drills with thin margins for example, reduces the contact with the hole surface, minimising friction between the cylindrical land and the hole walls, decreasing work hardening and temperatures generated.

Positive point geometries ensure excellent chip breaking and evacuation, while a specially designed web combines the benefits of maximum rigidity with space for efficient chip removal, reducing machine downtime.

Coatings and coolant
Significant heat is generated during machining of stainless steel, resulting in plastic deformation and severe crater wear. Therefore, a generous flow of cutting fluid removes heat from the cutting edge, helps chip breaking and improves dimensional stability of the component.

When using flood coolant, it is important to ensure a plentiful supply as any period of coolant starvation can cause temperature fluctuations. This can cause thermal cracking, resulting in reduced tool life. Cutting tools with through coolant also provide an instant reduction in temperature and supports chip evacuation.

Meanwhile, a Titanium Aluminium Nitride (TiAlN) coating is ideally suited for machining stainless steel as it holds its hardness at higher temperatures due to a layer of aluminium oxide, helping to transfer the heat away from the cutting tool.

The high strength of stainless steels combined with their high ductility makes chip breaking more difficult. This increases the risk of vibration, which can affect surface finish quality and reduce the service life of the tool or insert.

To address this, always make sure tooling and work pieces are stable and well clamped. Always keep tool overhang to a minimum, especially when drilling or internal turning. To help reduce vibration, use sharp tools or inserts with a small nose or corner radius.

Ferritic & Martensitic
The machinability of ferritic and martensitic stainless steels shows a resemblance to that of ISO P: Steel. Normal chromium content is 12-18 per cent, with only small additions of other alloying elements.

Ferritic materials are used in shafts for pumps, steam and water turbines, nuts, bolts, hot water heaters, and in the pulp and food processing industries. Martensitic steels can be hardened and are, as a result, used for edges in cutlery steel, razor blades and surgical instruments.

Machinability of ferritic and matensitic stainless steels is good and very similar to low alloyed steels.

Austenitic & Super-Austenitic
Austenitic stainless steels are the most commonly used ISO M material, accounting for 70 per cent of all stainless steel machined. This is due primarily to their very good resistance to corrosion.

The most common composition is 18 per cent chromium and 8 per cent nickel. Steel with greater corrosion resistance is created by adding two to three per cent molybdenum, often called “acid-proof steel” or type 316.  Super-austenitic stainless steels have a nickel content of more than 20 per cent.

Austenitic and super-austenitic stainless steels are used where good resistance against corrosion is required. Typical industry sectors include the chemical, pulp and food processing industries. It is also used in aircraft exhaust manifolds.

Austenite stainless steel produces tough, long, continuous chips that are difficult to break. It is prone to work hardening during machining, producing hard surfaces and chips which lead to notch wear. It also creates adhesion and produces built-up edge, resulting in poor surface finish and reducing tool life.

To minimize this, avoid using tools with worn edges which could accelerate tool wear and cause breakage. Make regular checks for signs of wear and change tools or inserts regularly. Also, try to avoid any dwells or pauses in the cutting process as this will cause heat build-up and increase work hardening.

A high rake angle reduces heat generated during milling, minimising work hardening.

Duplex
Adding nickel to a ferritic chromium based steel will form a mixed base structure containing both ferrite and austenite. This is known as a duplex stainless steel.

Duplex materials have a high tensile strength and maintain very high corrosion resistance.  Super-duplex and hyper-duplex indicate higher content of alloying elements and even higher corrosion resistance.

Chromium content between 18-24 per cent and nickel content between 4-7 per cent are common in duplex steels, producing a ferritic share of 25-80 per cent.

Duplex stainless steels are used in the chemical, food, construction, medical, cellulose and paper making industries, and in processes that include acids or chlorine. They are often used in equipment related to off-shore oil and gas applications.

Machinability of Duplex is generally poor due to high yield point and high tensile strength. Higher content of ferrite – above 60 per cent – improves machinability.

Dormer Pramet has developed a comprehensive assortment of indexable and rotary cutting tools to support machining of stainless steel.

Its solid carbide drill for applications up to 8xD has been specifically developed to overcome problems typically associated with deep-hole drilling of stainless steel. Created within the Dormer product portfolio, the R459 broadens the existing MP-X range which already consists of 3xD and 5xD solid carbide multi-material drills.

Meanwhile, a versatile range of OEHT octagonal inserts for cutting depths 4 – 10 mm, alongside REHT (round) and XEHT (wiper) inserts, is suitable for stainless steel.

By utilising eight cutting edges – the highest number available for positive inserts – the new range provides an economical offer for customers, while the wiper insert option boosts feed rate capabilities and surface finish quality.

Courtesy: Dormer Pramet
 

Pramet aims to increase the accuracy of indexable hole-making with the launch of a versatile new chip-breaker. Suitable for machining low carbon and soft stainless steels, the SD geometry supports both Pramet’s SCET and XPET ranges.

The SD (soft drilling) chip breaker has been specifically designed to provide improved stability and productivity when drilling low strength soft and long-chipping material, where the balance of forces between the inserts becomes more difficult to maintain.

Part of a wider launch of new products announced by Dormer Pramet in November 2015, the chip-breaker’s positive geometry with stabilizer provides reliable chip evacuation, minimal vibration and low cutting forces. This results in a quieter and more stable machining process.

The addition means Pramet can offer a greater choice of grades, geometries and designs of inserts for indexable hole-making.

Its existing UD (universal drilling) geometry is suitable for machining most medium and high strength steels, while grades D8345, D8330 and D9335 provide a number of options for Pramet’s 800D line of 2D-5D indexable drills.

Marcel Nunes, product manager for indexable hole-making at Dormer Pramet, said: “A key requirement for any indexable drilling task is accurate hole-tolerance and straightness. This is best achieved when the cutting forces on the inner and outer inserts are balanced.

“However, the cutting conditions for both inserts are typically very different. The outer insert cuts smoothly at maximum speed, while the inner insert has to work closer to zero cutting speed, shearing rather than cutting and enduring higher impact forces.

“When this in-balance gets too large the drill starts to move, deflecting it off course. This results in greater vibration and poor-hole quality, unreliable chip evacuation and reduced tool life.

“When machining low strength soft and long-chipping steel and stainless steel the balance of forces becomes even more difficult to maintain. Our new SD chip breaker has been specifically designed to provide better stability and productivity when drilling these materials.””

An overview of all the new indexable ranges launched by Dormer Pramet in November 2015 is available in its latest product brochure. To order a printed copy or for more information contact your local Dormer Pramet sales office.

Pramet’s popular shoulder milling range has been expanded with a new program of cutters, geometries and inserts.

This includes a program of helical cutters for roughing applications. Offering a depth of cut up to 108mm, the cutters are suitable for use with Pramet’s versatile ADMX 16 inserts and support medium machining of most engineering materials including cast iron, stainless steel and aluminium alloys.

The large clearance between the cutting teeth, combined with internal coolant delivery, promotes efficient chip evacuation. The axial clamping of inserts on the end teeth increases milling stability. This creates less noise and vibration which, in turn, also reduces tool wear.

Karel Tiefenbach, indexable milling product manager at Dormer Pramet, said: “The new range of helical cutters offers additional performance and reliability for a variety of operations including shoulder milling, grooving and contouring.

“Our ADMX 16 range is one of our most popular inserts. The creation of a new milling cutter further expands this versatile program. Customers can now use the same insert type for several milling cutters and applications, offering a more efficient and reliable service.”

As part of the launch, two new positive geometries – MF and MM – have been added for milling stainless steel, super alloys, low carbon steel and non-ferrous materials.

MF is a sharp and highly positive geometry, ideal for light machining and finishing operations.

MM is a universal sharp and highly positive geometry with stabilised cutting edge for finishing and semi-roughing operations.

For use with shoulder milling inserts ADMX11 and ADMX16, as well as the LNGX12 range, the new geometries’ positive rake angle provides low cutting resistance, reduced cutting forces and less power consumption.

Meanwhile, Pramet has also expanded its range of inserts for economical shoulder milling. New radii and geometries have been added to the LNGU/LNMU16 assortment to provide greater choice.

A further four radii options are now available offering a range of sizes from 0.8mm to 4.0mm. New geometries include F, M and R for machining stainless steel, steel and cast iron. A highly positive geometry FA is for copper and aluminium.

An overview of all the new indexable ranges launched by Dormer Pramet in November 2015 is available in its latest product brochure. To order a printed copy or for more information contact your local Dormer Pramet sales office.

Pramet has introduced two new positive geometries and grades for turning applications in difficult to machine materials (DTMM).

Suitable for a variety of turning applications, the SF and SM geometries have been launched to support the machining of materials such as high temperature alloys and stainless steel.

Part of Dormer Pramet’s second product launch of 2015, the SF geometry features a sharp, positive rake of 14.5°. It is suitable for finishing applications in continuous cut with very low forces.

The SM geometry has a positive rake of 13° and is a wear-resistant, universal geometry for medium machining (finishing up to roughing) and suitable for continuous and interrupted cut.

Both geometries are available in a variety of grades and have been designed to promote low cutting forces and prevent work-hardening. This helps to reduce the risk of vibration when turning thin-walled components.

In addition to the new geometries, two new turning grades have been unveiled by the global cutting tool manufacturer.

The PVD coated T6310 grade features a special sintering process which enhances cutting edge reliability and strength. Its new substrate with intermediate Cobalt content provides additional hardness and increased abrasion resistance to offer greater reliability and prolonged tool life.

The T6310’s triple coating provides durability for higher cutting speeds used when machining stainless steel, heat-treated and hardened materials. It is suitable for use with the new SM and SF geometries, as well as Pramet’s existing NF and RM geometries, with a total of 89 inserts now available.

Josef Bittner, product manager for turning at Dormer Pramet, said: “The thermal conductivity of stainless steel, nickel and titanium tends to be low, but with high cutting speeds and feeds required during machining, the cutting edge can quickly become overheated, shortening tool life.

“Machining with coolant reduces these effects, but the constant change of temperature at the cutting area causes heat stresses, resulting in thermal cracks and, again, poor tool life.

“We therefore saw a need to create a new grade with the right combination of substrate and coating to enhance resistance to thermal cracking. Our new T6310 grade achieves that objective.”

Meanwhile, Pramet’s new H07 uncoated grade offers good heat conductivity and high wear resistance required for turning titanium and alloys. Its fine grain substrate with low Cobalt content offers resistance to pitting as well as plastic deformation. It is available in the new SF geometry.

Josef added: “These latest products will be of use in extreme environments where they are subjected to tremendous heat and corrosion, for example in the general machining, oil and gas, automotive, medical industry, marine and power generation sectors.”

An overview of all the new indexable ranges launched by Dormer Pramet in November 2015 is available in its latest product brochure. To order a printed copy or for more information contact your local Dormer Pramet sales office.

A completely new range of cutters and inserts for economical face milling of stainless steel form part of a launch of products by Pramet.

The versatile range includes OEHT octagonal inserts for cutting depths 4 – 10 mm, alongside REHT (round) and XEHT (wiper) inserts.

By utilising eight cutting edges – the highest number available for positive inserts – the new range provides an economical offer for customers, while the wiper insert option boosts feed rate capabilities and surface finish quality.

Pramet’s new double positive 45° milling cutter, S45OE, is available in diameters up to 200mm and supports internal coolant delivery.

Its versatile design allows the same cutter body to be used with both the octagonal inserts for face milling and the round inserts for face and copy milling applications.

Suitable for use even on machines with limited power, the combination of new inserts and cutter offer high metal removal rates with low cutting force. The risk of chatter is also reduced – an important consideration when machining valuable components.

Karel Tiefenbach, indexable milling product manager at Dormer Pramet, said: “Our latest package of products for stainless steel offers additional economical and versatile options for the customer. The cutters design features positive axial and radial face angles, promoting a good cutting action and directing chips away from the work-piece. Our S45OE range offers a wider selection of diameters and enhances our line of cutters with double positive geometry. This is especially beneficial when the work-piece is fragile, the fixture is unstable or the component material has the tendency to work harden – a common issue when machining stainless steel.”

For use with the OEHT inserts, three new positive geometries – MF, MM and M – have been introduced for various cutting conditions.

The MF is a sharp and highly positive geometry for finishing applications in stainless steel, mild carbon steel and non-ferrous metals. MM is a sharp and positive geometry for machining stainless steel in medium cutting conditions.

The M is a positive geometry with stabiliser – suitable for difficult cutting conditions in materials such as carbon steels and harder stainless steel.

The new geometries offer reduced cutting forces and increased durability for machining with or without coolant.

Dormer Pramet has added a range of carbide rotary burrs to enhance its support tools program for general machining processes.

It is the first time that burrs will be available under the Dormer product brand, with a comprehensive assortment of designs and shapes to choose from, including ball nosed cylinder, pointed tree, oval, flame, 60° and 90° countersinks, cones and inverted cones varieties.

The introduction of the burrs is part of a wider product launch by Dormer Pramet on 1 April 2015 – the first combined unveiling since Dormer and Pramet merged last year.

Dormer’s wide selection of burrs provides numerous options to machine a range of materials, including hardened steel, non-ferrous materials and plastics.

Its combination of carbide head and steel shank (above 6mm) provides an ideal mix of rigidity and strength. This feature reduces vibrations, resulting in a consistent and secure performance, as well as an improved tool life. A double cut design on Dormer’s burrs improves ease of control, increases metal removal rate and breaks swarf into manageable pieces.

Also, the ball end geometry incorporates skip flute grinding which improves cutting action closer to the centre, reducing the chance of swarf congestion and increases strength.

Alternatively, the aluminium cut option makes it the first choice for non-ferrous materials and plastics. The high helix and rake angle offers large flute volume for rapid material removal rates. Dormer’s burrs are available with TiAlN coating to increase tool life in difficult conditions and help to resist ‘built-up edge,’ which is common for cutting tools with small flute volumes.

Note: The merger of round tools manufacturer Dormer Tools and cemented carbide tooling specialist Pramet Tools was instigated in 2014. The combined product programme now encompasses a comprehensive range of rotary and indexable drilling, milling, threading and turning tools for the general engineering sector. An expanded sales and technical support service extends to over 30 offices serving more than 100 markets worldwide. These are supported by state-of-the-art production facilities in Europe and South America and a global distribution network consisting of five strategically placed hubs.