US Patent 7568865 Thread forming tool assembly

The thread forming tool assembly includes a steel holder block, a carbide tool and a threaded fastener. The steel holder block has block top, bottom, first side, second side, base end and a carbide tool engaging end. A tool engaging end, of the holder block includes a first holder tool engaging surface and a second holder tool engaging surface that diverge from each other. A carbide tool has a first holder engaging surface that engages the first holder tool engaging surface and a second holder engaging surface that engages the second holder tool engaging surface. Thread forming exerts forces on the carbide tool that urge the first and second holder engaging surfaces toward engagement with the tool engaging end of the holder block.