Sandvik CoroMill 390 is One Tool for Many Applications

From general milling of standard metals to milling complex deep pockets for producing aerospace components out of modern metal materials, Sandvik’s CoroMill 390 is a versatile cutting tool with broad functionality.

SandVil CoroMill 390 can be used for general milling and complex projects with challenging materials.
Sandvik’s CoroMill 390 can be used for general milling and complex projects with challenging materials.

Sandvik’s “390” cutter family can be used for myriad applications by integrating a large, versatile program, including versions for shoulder milling and long-edge milling. Cutter inserts generate a good, quality 90-degree shoulder and are ideal for ramping and helical interpolation.

For instance, to produce precise contours without steps in repeated shoulder milling operations, the company offers close-tolerance inserts and an exact insert position. The smooth cutting action of CoroMill 390 limits radial cutting forces, which minimizes bending and generates good wall perpendicularity.

CoroMill 390 insert size 07
CoroMill 390 insert size 07.

The CoroMill 390 assortment of inserts includes cutters with size 07 inserts in dimensions specifically designed for key slots. With a tool diameter that is 0.3 mm (0.012 in.) smaller than the slot width, a suitable amount of stock is left for the subsequent finishing operations.

In another example, using helical interpolation and linear ramping to create holes from a solid workpiece requires a strong insert face geometry. The CoroMill 390 inserts are developed to withstand the stress caused by steep ramping or demanding interpolation, giving a low-vibration process with even tool life.

Plunge milling using the CoroMill 390 produces less stress on your machine spindle because of its vibration damping attributes. Because of this, it is suitable for unstable machines, deep slots, difficult-to-machine areas, and high-radial engagements such as corners.

Incorporating new steel grade
CoroMill 390 covers many applications with a large, versatile program.
The CoroMill 390 can be used for many applications because of its large, versatile tool program.

CoroMill 390 is made with Sandvik’s robust steel milling grade GC1130, which is made with the Zertivo PVD coating process that reliably performs even in unstable or challenging conditions such as disparate temperature variations.

The Zertivo process includes a complex set of steps, including pumping, heating, etching, coating, and cooling. Process parameters such as temperature, gas flow, and pressure are crucial to the final tool performance.  Each grade is produced with the exact right conditions for that specific grade. The result is improved adhesion between substrate and coating as well as optimized cutting-edge integrity.

The result is great edge-line security and reduced flaking. This makes the insert resistant to chipping.

In addition, the tool’s high-Cr (Chromium) content, in its fine-grain substrate, is optimized to withstand edge-line chipping and cracks arising from difficult machining and demanding conditions, such as temperature variations.

Keep Silent

Some of the tools incorporate the company’s Silent Tools™ technology. Sandvik Coromant’s endmill for small diameters, for instance, available with size 07 inserts, is a versatile cutter ideal for shoulder milling, deep shoulder milling, edging, linear and helical ramping, plunge milling, slot milling and face milling.

Insert sizes 07 and 11 are available with Sandvik’s Silent Tools™ damping technology. The upgraded Silent Tools dampening technology will allow machine shops to machine deep pockets for products such as titanium aerospace frame parts.

Silent Tools™ CoroMill® 390 cutters
Silent Tools™ CoroMill® 390 cutters.

Silent Tools provide light-cutting insert geometries and high-performance grades that deliver low-cutting forces and vibration-free machining for secure, cost-effective milling. The tool holders are designed to minimize vibrations through a dampener inside the tool body.

The CoroMill 390 Silent Tools can be ordered in diameters from 20 to 32 mm. It is available for both the new insert size 07, as well as insert size 11, with options for either cylindrical shank or Coromant Capto coupling.

Challenges and solutions

Sandvik Coromant calls the CoroMill 390 a “go-to cutter.” As evidence of this, Sandvik has detailed some typical challenges and its solutions.

For instance, pocket milling can be challenging to produce efficient and secure cavity opening. Using helical interpolation and linear ramping to create holes from a solid work piece requires strong insert face geometry. CoroMill 390 inserts are developed to withstand the stress caused by steep ramping or demanding interpolation, providing a low-vibration process with even tool life.

Here is a look at some other challenges:

Process: Slot milling
Challenge: Chip evacuation and vibration.
Solution: Insert geometries designed for ideal chip formation and evacuation. When milling with large engagements, vibration often causes rapid tool wear. The light cutting inserts of CoroMill 390, combined with cutters with optimized differential pitch, offer a low-vibration milling process.

Process: Face milling/Key Slot Milling
Challenge: Metal removal rate and surface finish.
Solution: Durable CoroMill 390 inserts are capable of high cutting parameters. -L geometries designed for milling with low cutting forces are perfect for facing surfaces with a shiny finish and close tolerances.

Order online or for more information on CoroMill 390, contact a Steiner Metalworking sales representative at (800) 323-TOOL.

Sandvik CoroTurn 300 Metal Cutting Tools Offer Quality Turning

For longitudinal and face turning, Sandvik Coromant now offers CoroTurn 300 metal cutting tools that are designed for high-volume, OD steel-turning operations.

The Sandvik CoroTurn 300 metal cutter features stable insert clamping. Its eight-edged inserts, with 80 degree cutting edges, provide high-chip control, and improved surface finish. The inserts ensure good heat transformation for predictable performance and wear. More edges also mean fewer inserts required, which in turn means better inventory control, and less carbide per edge means less waste and material to recycle.

Keep it Steady

Stable insert clamping for the CoroTurn 300 is accomplished through the company’s patented iLock interface. All machining generates forces on the metal cutting tools and these forces can cause micro-movements of the insert in its seat. Even the smallest movements can negatively affect tool performance and result.

Forces on the cutting tool create micro movement that can affect cutting tool performance.

To counter this, the iLock system securely locks the insert in place and provides tool accuracy to within ±0.05 mm (0.002 in.), giving the operator indexing repeatability for a better surface finish and increased tool life.

Tools with iLock design have rails or serrations on the tool holder and corresponding slots on the insert for tight locking. This prevents the cutting forces from affecting the tool position.

Keep it Cool

Another way the CoroTurn 300 offers enhanced chip breaking capabilities is through high-precision (HP) over and under coolant. Coolant from above controls the chip breaking for secure machining while under coolant controls the temperature for long and predictable tool life. Other features of the tool are the Coromant Capto interface in a variety of sizes and the Quick Start (QS) shanks, which enable quick tool changes and easy coolant connections for maximized production time.

John Winter, turning product specialist for Sandvik Coromant, said, “The CoroTurn 300 integrates the latest advances in iLock, Inveio [coating] and high-precision coolant technology to take steel turning into the next century using an insert with eight, 80 degree cutting edges. This is the perfect tool for high volume outer diameter (OD) steel turning applications where tool life and process security is a must.”

Sandvik Coromant recommends only under-coolant when the feed rate exceeds 0.2 mm/revolution and the depth of cut (DOC) is larger than the nose radius of the insert. Under these conditions, over-coolant might cause minor edge wear and increase crater wear in steel, and make it difficult to evaluate this wear. Conversely, if the DOC is either smaller than the nose radius or the feed rate is slower than 0.2 mm/revolution, using both over- and under-coolant is recommended, according to the Website.

For example, in one automotive application (an outer CV joint) a Sandvik Coromant CoroTurn 300 insert with -L4 geometry was used to turn low-alloy steel (P2.1.Z.AN) with 3 bar (43.5 psi; 300kPa) of coolant pressure at a feed rate of 0.35 mm/revolution and a 2.5-mm DOC.

The CoroTurn (CT) insert delivered a 158% improvement in tool life versus an insert with -PF geometry, while the same CT300 insert delivered a 200% tool life improvement using only under-coolant.

Keep it Coated

The eight-edged inserts for the CoroTurn 300 are available in grades GC4325 and GC4315 featuring Inveio coating, a unidirectional crystal orientation for high wear resistance and long tool life. The unique insert design has excellent chip breaking capabilities and less carbide per edge, which reduces the impact on our environment with less material to waste or recycle. Plus, more edges allow for better inventory control.

The coating is applied through a chemical vapor deposit process (CVD) that through a chemical process turns a solid firm into a gaseous deposit onto the substrate.

Typically, when using this process, the coatings’ crystal growth direction is random. When developing Inveio™, Sandvik found a way to control the growth in this coating layer. Researchers were able to ensure that all of the crystals lined up in the same direction, with the strongest part towards the top surface.

The tightly-packed uni-directional crystals create a strong barrier towards the cutting zone and chip and greatly improves crater wear and flank-wear resistance. Heat is more rapidly lead away from the cutting zone, helping the cutting edge stay in shape for longer times in cut.

For more information on the CoroTurn 300, contact your Steiner Metalworking application engineer at (800) 323-TOOL.

CoroTurn Prime Revolutionary Turning Tool Cuts Across Many Directions

Sandvik Coromant Introduces CoroTurn Prime and Prime Turning

When Sandvik Coromant released a video in support of its new PrimeTurning™ turning technology, the video almost appeared to be going in reverse. The cutting tool traversing from chuck to the end of the workpiece. Had it been going in reverse, however, material would have magically gone back on the blank, as opposed to the long strips of material being removed first along one axis and then another.

PrimeTurning is a new turning method that enables turning in all directions. Unlike conventional turning operations, PrimeTurning allows machine shops, OEMs and other users to complete longitudinal facing and profiling operations with a single tool. In addition to the prime turning technology, the company released two types of tooling, an A-type for fine finishing and a B-type for roughing applications.

With this forward-and-back cutting capability, and its innovative tooling technology, Sandvik Coromant believes that some applications could achieve productivity increases of more than 50% as compared to conventional techniques.

For instance, Cutting Tool Engineering magazine reported on an Italian manufacturer who reduced the cycle time for machining a shaft from 2.42 to 1.36 minutes and extended the tool life per edge from four pieces to nine by using the PrimeTurning system.

According to the report, a competitor’s conventional insert ran at a cutting speed of 150 m/min., a feed rate of 0.012 ipr, and a DOC of 0.079 in. By contrast, the CoroTurn® Prime B-type roughing insert ran at double the cutting speed and DOC, and a feed of 0.032 ipr when turning forged, ASTM B564 nickel alloy with a hardness of 250 HB.

Major reasons for the reported success of the PrimeTurning technology is due to the small entering angle relative to the feed direction, as well as a higher lead angle that allows the user to cut substantially faster. The turning operation creates thinner, wider chips that spread the load and heat away from the nose radius. In addition, as cutting is performed in the direction moving away from the shoulder, there is no danger of chip jamming, which can occur if chips are pushed against the shoulder during turning.

Entering and lead angles:
A-type KAPR = 30°, PSIR = 60°
B-type KAPR = 25°, PSIR = 65°

“Experienced operators know that a small entering angle allows for increased feed rates,” said Håkan Ericksson, Global Product Specialist at Sandvik Coromant. “However, in conventional turning they are restricted to using entering angles of around 90 degrees to reach the shoulder and avoid the long, curved chips that a small entering angle characteristically delivers. PrimeTurning solves these problems by combining a perfect reach at the shoulder and the application of 25 degrees to 30 degrees entering angles with excellent chip control and maintained tolerances. This innovation presents countless possibilities to perform turning operations in much more efficient and productive ways. It’s not just a new tool, but a totally new way of turning.”

Supporting Technologies

PrimeTurning is supported by the introduction of two dedicated CoroTurn Prime turning tools, part of the CoroTurn insert tooling line, and the PrimeTurning code generator, which supplies optimized programming codes and techniques.

The PrimeTurning methodology and CoroTurn Prime A-type tool (left) and B-type (right) enable turning in all directions.
The PrimeTurning methodology and CoroTurn Prime A-type tool (left) and B-type (right) enable turning in all directions.

The new turning tools include:

  • The CoroTurn Prime A-type tool with three 35° corners designed for light roughing, finishing and profiling.
  • The CoroTurn Prime B-type tool with strong corners designed for rough machining.

Suitable for ISO P (steel), S (heat-resistant super alloys and titanium) and M (stainless steel) category materials, nine CoroTurn Prime A-type and six CoroTurn Prime B-type inserts are currently available, with expansion to other material​s envisioned for the future. The inserts are supported by 52 variants of tool holder, including Coromant Capto®​, CoroTurn QS and shanks.​

The ​CoroTurn Prime inserts feature three edges per corner. One edge each for longitudinal, facing and profiling thus distributing the wear over a longer edge and not just the insert tip. It also moves heat away from the cutting zone that helps inserts last substantially longer.

Sanvik Coromant also developed a Code Generator to develop specialized toolpath strategies and take full advantage of CoroTurn Prime insert design.  The generator supplies programming codes and techniques to set up maximum parameters and variables for a particular application to secure maximum output in ISO P steels, ISO M stainless steels and ISO S heat-resistant super alloy (HRSA) materials.