Thread Cutters OR Chasers

Thread Cutters OR Chasers

Thread Cutters OR Chasers - Self opening die heads and collapsible taps are assembled tools incorporating inserted cutters called chasers, the cutting edges not being integral with the die (or tool) body as is the case of solid dies and taps.

When a thread is completed, the individual cutting components i.e., chasers are automatically pulled clear of the work so that the tool head can be withdrawn.

Cutting threads with single point tools is an operation with a comparatively low output because a great number of passes are required to cut the thread to the full depth. The output is especially low when the thread is chased to a shoulder since in this case, regardless of the kind of thread being cut, the workpiece speed should not exceed 50 rpm.

Thread chasers are, in essence, several single point threading tools joined together in a row (from 2 to 8). Chasers have a chamfer at the entering end, with several teeth (usually 2 or 3) ground off at a definite angle to distribute the cutting action, and a sizing section consisting of the rest of the teeth. Due to its multiple teeth and distributed cutting action, a chaser can cut threads in a much smaller number of passes.

Consequently, its output is higher than that of a single point tool. Thread chasers may be either the block type or circular.