Thread Whirling Toolholder

May 01, 2015

Designed for single-spindle Swiss screw machines, the latest thread whirling toolholder from EXSYS Tool Inc. productively machines high-precision OD threads in challenging materials.

An inexpensive alternative to dedicated thread whirling machines, the EXSYS toolholder is ideal for processing micro-components with long, slender thread profiles such as medical bone screws, dental implants and aerospace fasteners.

The ring-shaped toolholder has an adjustable range of zero and 15 degrees to accommodate most profile shapes. It employs a maximum input and output rpm of 6,000 and maximum torque output of 13 Nm to threadmill rough stock at extremely high speeds.

Because of its open interface, the EXSYS toolholder accommodates cutting tool inserts from different suppliers. The chosen inserts, however, must be identical and evenly spaced for the thread whirling process. The cutting edges of these inserts face the toolholder's opening and rotate around the bar stock to cut an external thread. The machine's Z-axis longitudinally feeds the toolholder at high speeds, while the bar stock rotates at slow speeds via C-axis control. Each insert then takes its cut of the material as the toolholder whirls around the bar stock.

Thread whirling with the EXSYS toolholder has several advantages over traditional, single-point threading operations. Thread whirling increases tool life by distributing the cutting load over several inserts. The process also cuts threads to their full depths, including full deburr, in one pass. Single-point threading, on the other hand, has one cutting edge, taking the entire cutting load over several passes. Furthermore, in thread whirling, users can freely select their speeds and feeds to suit ideal cutting conditions.

Also, because the EXSYS toolholder's cutting action takes place near the machine's guide bushing, users achieve maximum rigidity during the threading process, which ultimately results in accurate, quality components with high surface finish.

The EXSYS thread whirling toolholder mounts to one of the rotary tool stations on the Swiss screw machine and offers fast cutting tool change outs.

Related Glossary Terms

  • bushing

    bushing

    Cylindrical sleeve, typically made from high-grade tool steel, inserted into a jig fixture to guide cutting tools. There are three main types: renewable, used in liners that in turn are installed in the jig; press-fit, installed directly in the jig for short production runs; and liner (or master), installed permanently in a jig to receive renewable bushing.

  • outer diameter ( OD)

    outer diameter ( OD)

    Dimension that defines the exterior diameter of a cylindrical or round part. See ID, inner diameter.

  • threading

    threading

    Process of both external (e.g., thread milling) and internal (e.g., tapping, thread milling) cutting, turning and rolling of threads into particular material. Standardized specifications are available to determine the desired results of the threading process. Numerous thread-series designations are written for specific applications. Threading often is performed on a lathe. Specifications such as thread height are critical in determining the strength of the threads. The material used is taken into consideration in determining the expected results of any particular application for that threaded piece. In external threading, a calculated depth is required as well as a particular angle to the cut. To perform internal threading, the exact diameter to bore the hole is critical before threading. The threads are distinguished from one another by the amount of tolerance and/or allowance that is specified. See turning.

  • toolholder

    toolholder

    Secures a cutting tool during a machining operation. Basic types include block, cartridge, chuck, collet, fixed, modular, quick-change and rotating.