Tungaloy Further Improves Its CBN inserts’ Cost per Edge, Reliability, and Chip Control in Finish Hard Turning Applications
Iwaki, November 2021 — Developed to ensure good chip breaking and control during finish machining of hardened steel parts, Tungaloy’s CBN inserts with HP-style chipbreaker are now available in a double-sided WavyJoint style that provides maximum tool reliability and stability.
An innovative HP-style chipbreaker is developed to guarantee superior chip control during hard part turning at 0.2 mm (.008″) or lighter d.o.c. The chipbreaker is uniquely designed with an optimal distance between the cutting edge and the chip redirector. This design minimizes crater wear development on the rake face for maximum tool life and also helps lighten cutting forces during machining, eliminating chatter marks and part scraps for improved machining stability.
20 new inserts in HP-style chipbreaker are now available in WavyJoint style; namely, 4QS-CNGG1204..-HP, 4QS-DNGG1504..-HP, 6QS-TNGG1604..-HP, and 4QS-VNGG1604..-HP inserts. Conventionally, CBN cutting tips are brazed onto the seats ground, usually on one side, on a cemented carbide insert body to form a CBN insert. The WavyJoint technology further enhances the bond of CBN cutting tips on negative inserts with 160% increased brazing surface between the CBN tip and carbide insert body. Also, the technology uses 200% larger volume CBN tips for improved insert reliability and tool life. In addition, CNGG1204..-HP inserts are also available in wiper geometry, increasing surface finishing quality.
Two insert grades are available: versatile BXA20 that covers continuous to interrupted cuts at low to medium cutting speeds and BXA10 that demonstrates exceptional wear resistance in continuous cuts of hardened steel, providing reliability and long tool life.
Related Glossary Terms
Condition of vibration involving the machine, workpiece and cutting tool. Once this condition arises, it is often self-sustaining until the problem is corrected. Chatter can be identified when lines or grooves appear at regular intervals in the workpiece. These lines or grooves are caused by the teeth of the cutter as they vibrate in and out of the workpiece and their spacing depends on the frequency of vibration.
Groove or other tool geometry that breaks chips into small fragments as they come off the workpiece. Designed to prevent chips from becoming so long that they are difficult to control, catch in turning parts and cause safety problems.
- cubic boron nitride ( CBN)
cubic boron nitride ( CBN)
Crystal manufactured from boron nitride under high pressure and temperature. Used to cut hard-to-machine ferrous and nickel-base materials up to 70 HRC. Second hardest material after diamond. See superabrasive tools.
- hard turning
Single-point cutting of a workpiece that has a hardness value higher than 45 HRC.
Angle of inclination between the face of the cutting tool and the workpiece. If the face of the tool lies in a plane through the axis of the workpiece, the tool is said to have a neutral, or zero, rake. If the inclination of the tool face makes the cutting edge more acute than when the rake angle is zero, the rake is positive. If the inclination of the tool face makes the cutting edge less acute or more blunt than when the rake angle is zero, the rake is negative.
Workpiece is held in a chuck, mounted on a face plate or secured between centers and rotated while a cutting tool, normally a single-point tool, is fed into it along its periphery or across its end or face. Takes the form of straight turning (cutting along the periphery of the workpiece); taper turning (creating a taper); step turning (turning different-size diameters on the same work); chamfering (beveling an edge or shoulder); facing (cutting on an end); turning threads (usually external but can be internal); roughing (high-volume metal removal); and finishing (final light cuts). Performed on lathes, turning centers, chucking machines, automatic screw machines and similar machines.
- wear resistance
Ability of the tool to withstand stresses that cause it to wear during cutting; an attribute linked to alloy composition, base material, thermal conditions, type of tooling and operation and other variables.
Metal-removing edge on the face of a cutter that travels in a plane perpendicular to the axis. It is the edge that sweeps the machined surface. The flat should be as wide as the feed per revolution of the cutter. This allows any given insert to wipe the entire workpiece surface and impart a fine surface finish at a high feed rate.