Conventional "bump" knurling methods are undesirable for smaller diameter parts because the forces deflect the workpiece, according to Genevieve Swiss Industries Inc., Westfield, Mass. To control this problem, the company recommends using a straddle knurl holder to provide support to the workpiece while the knurling operation is performed.
Low profile straddle knurling holders are adjustable to accomodate a range of part diameters.
Specifically designed for Swiss-type machines, the low profile straddle knurl holders from Genevieve Swiss are said to keep interference to a minimum within the tooling layout of most machines while enabling use of adjacent tool positions to maximize tooling capacity.
The holders are suitable for machines such as Citizen, Star, Tsugami, Tornos, Hanwha as well as Ganesh turning centers.
Related Glossary Terms
Cone-shaped pins that support a workpiece by one or two ends during machining. The centers fit into holes drilled in the workpiece ends. Centers that turn with the workpiece are called “live” centers; those that do not are called “dead” centers.
Chipless material-displacement process that is usually accomplished on a lathe by forcing a knurling die into the surface of a rotating workpiece to create a pattern. Knurling is often performed to create a decorative or gripping surface and repair undersized shafts.
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.