Milling is a backbone operation in most shops. To help shops achieve higher milling productivity, longer tool life and lower production costs, manufacturers are constantly raising the bar of cutting-tool technology. Innovative geometries, grades, coatings and cutting techniques result in increased performance and economies when cutting a variety of materials. Here are some of the latest innovations to improve milling efficiencies:
Cast ironA uniquely engineered tangential-style milling cutter from Sumitomo Electric Carbide Inc. (www.sumicarbide.com) has a finepitch design to produces low cutting forces for high production and fine surface finishes when cutting gray and ductile cast irons.
Sumitomo’s new SumiEdge Mill is an 88-degree tangential milling cutter that allows for the use of all eight cutting edges – first by rotating the LNMX insert within the pocket, and then by switching the insert from one cutter to the next (using both left and right-hand cutters). The tools are available in 3- and 6-in. diameters for both left and right milling cutters.
According to Sumitomo, its new ACK200 and ACK300 grades provide stable cutting performance and long tool life. The ACK200 grade features a Super FF coating with an ultrafine TiCN layer for anti-adhesion and wear resistance during general-purpose machining of gray and ductile cast iron.
The ACK300 grade uses a multilayered Super ZX coating, consisting of nanometer thick TiAIN and AlCrN layers, coupled with a fine-grained super tough substrate for fracture resistance.
AluminumWith a new insert-pocket design and direct-mount insert clamping mechanism, ValMILL V650 high-velocity face milling systems from Valenite LLC (www.valenite.com) are for highspeed machining of aluminum alloys. The tools, available in diameters of 2 in. to 10 in., offer safe, rigid and chatter-free operations at speeds of up to 20,000 sfm for optimal utilization of PCD-tipped inserts for aluminum applications, and CBN tools for other workpiece materials.
The high rigidity of the insert mount, characterized by a closed wedge-lock pocket design —75 percent of the insert body is “armored” within the cutter body and clamping mechanism — is able to absorb high centrifugal forces.
Overall system strength is enhanced by incorporat ing a serrated insert face and matching pocket surface that helps align and secure the insert while preventing any lateral shift during operation.
Within the pocket, a hardened lock wedge is positioned at the underside of the insert, acting as a damper against vibrations. The easily replaced lock wedge is designed to break before the cutter body in case of collisions with the workpiece or fixturing.
The steel cutter body is hardened for rigidity and wear resistance from chip abrasion. According to information from Valenite, the direct-mount insert concept results in a more compact and durable clamping system than conventional style mechanisms. It allows a more aggressive pitch and higher density of inserts, allowing for greater feed rates and maximum removal rates. In addition, a oneand- a-half turn of the clamp screw relaxes the retention force of the wedge on the insert clamp for quick insert changeouts.
The V650 cutter also offers the ability to adjust each insert’s axial depth setting using a vibration-resistant adjusting screw without affecting the tool’s state of balance. Access to the axial adjustment screw is located out of the cutting zone and away from chip contamination. This access position also eliminates obstruction of tool-sensing devices.
A single-size Allen wrench is the only tool needed for use with the V650 units. The milling cutter also optimizes insert applicability by allowing the use of the same geometry and size insert for all cutter diameters, presenting up to 0.4-in. cutting edge length.
