Thread Milling

EdgeCAM’s Thread Mill (Mill Cycles menu) command allows you to create a thread up or down the vertical axis of the machine. The cycle supports straight, taper, multi-start and arc lead-in/lead-out options. You can also machine multiple threads within the same command.

Note that the thread units can differ from the units used for the rest of the part. If you get an unexpected result from this cycle, check the values you used for the cycle parameters.

This example shows four views of a single-start external thread with an arc lead in and out.

Normally, you start defining the thread by selecting an arc entity. This arc represents the major diameter of an external thread, or the minor diameter of an internal thread (see example). You can also digitise a point that represents the centre of the thread (when using the thread milling cycle with hole features for example). In this case, use the Major/Minor Diameter fields on the Thread tab to specify the major/minor diameter for the thread.

On the Depth tab, you can use the Level and Depth parameters to define the start and end heights for the thread. Alternatively, depths may be specified as distances above and below the defined geometry using the Upper and Lower Distance parameters. All measurements are taken from the bottom of the thread, so if you define an overlapping tool, the system mills a thread above this height.

On the Thread tab, the Thread Side parameter sets the thread as internal or external, and the Hand of Thread parameter sets the thread as left or right-handed. See Defining the Thread.

The thread's direction of cut depends on these parameter values and is explained under Determining the Thread Mill Cut Direction.