Tapping may be the most common method for putting threads into a hole, but it is not always the best method. Difficult-to-cut materials, small hole sizes, or threading close to the bottom of a blind hole can push the limits of tap capabilities. An alternative way to create threads and overcome these hurdles is through the use of a thread milling cutter. Spiralock® all-carbide thread milling cutters can be made to order to suit specific customer applications by adjusting the cutter diameter, neck length, and number of threads.
- Made to order
- Ability to adjust amount of material being removed by changing depth of cut
- Continuous spindle rotation – no need to stop and reverse the spindle when coming out of the hole
- Easy machining of difficult materials that produces short, controllable chips
- One cutter can produce varying diameters with a common thread pitch
- One tool for both right- and left-hand threads, as well as through or blind holes
- Partial thread removal at start of thread for cleaner assembly
- Full bottom threading with precise thread depth control
- Less cutting pressure for thin-walled workpieces
- Better thread surface finish quality and lower spindle torque
- Tool breakage does not necessarily result in workpiece rejection
How Thread Milling Works:
In thread milling, the workpiece remains stationary while the thread mill rotates at high speed and moves along a helical path. The tool is moved into position above the hole and then lowered into the hole before beginning the cut. The tool then moves out radially to touch the wall of the workpiece and begins its helical climb back out of the hole, controlled by a CNC program. Chip load and wear on the tool can be controlled by making several passes to generate the full thread profile. Thread milling speeds and feeds are dependent upon material tensile strength, hardness, and elongation characteristics. Spiralock® can assist customers in choosing a thread mill and recommending speeds, feeds, and number of passes.