For taps with recessed threads in the body, use the parallel bush series.
Cutters are case hardened. The feedscrew allows fine adjustment to the cutter.
All parts are interchangeable.
Fits old series 1/2in and 3/4in BS1010 flat seats. Complete with 17, 19, 20 and 25mm (11/16in, 3/4in, 13/16in, 1in) flat cutters and 2 tapered cones.