Punch Tap's Tooth Geometry Threads Faster

Emuge Corp.’s  Punch Tap line forms helical thread in cast and wrought aluminum alloys and similar lightweight materials. The product is made from a HSSE-PM alloy optimized for toughness and long wear. Its tooth geometry design shortens tool paths to e produc internal threads in less than half a second, consuming less energy and reducing threading time by 75 percent, according to the company. This makes the product ideal for high-volume applications.

Before threading, the tool punches into a pre-drilled hole and the first tooth of each flute creates a helical groove, which helps guide the tap to the application depth. The thread is then produced with a half left turn, and each tooth of the tap produces half a thread. After the threads are formed, the tap is retracted in a helical movement from the hole via the grooves. The finished, cold-formed thread is interrupted by two helical grooves offset by 180 degree. This design enables a tool path that is approximately 15 times shorter for an M6 thread with a depth of 15 mm compared to traditional cutting or cold-forming taps, the company says.

Thread strength is said to be comparable to conventionally machined threads from a thread depth of 2×D. This product is used for blind and through-holes, and the production of metric threads from M3 through M10 with thread depths ranging to 2×D (also available in sizes ranging #8 through ⁵/₁₆"). The taps have internal coolant supply using emulsion or minimum quantity lubrication (MQL). They are designed to be used on CNC machines programmed with a specialized punch tap cycle. Machine parameters will require adjustment for some applications.