US 7,575,520 B2
	Tap and a method of tapping
Neil Walter Lindh Adcock, Ragdale (United Kingdom)
Assigned to Adcock Technology Limited, Leicestershire (United Kingdom)
Appl. No. 10/566,918 PCT Filed Aug. 02, 2004, PCT No. PCT/GB2004/003304 § 371(c)(1), (2), (4) Date Feb. 03, 2006, PCT Pub. No. WO2005/014214, PCT Pub. Date Feb. 17, 2005.
Claims priority of application No. 0318227.6 (GB), filed on Aug. 04, 2003.
Prior Publication US 2006/0199654 A1, Sep. 07, 2006
Int. Cl. B21J 13/02 (2006.01)

U.S. Cl. 470—204  [470/198]

25 Claims

1. A tap adapted for formation of female screw-threads in a plurality of metal parts, each female screw-thread being capable of imparting translational motion to a threaded second member engaged therewith, the threaded second member having a matching male screw-thread and the translational motion occurring on relative rotation between the first metal part and the threaded second member, the tap being fluteless and comprising a threaded portion with a symmetrical triangular form thread, wherein the symmetrical triangular form thread has an angle of thread (α) in the range 29°-40° and radiussed crests with a radius of curvature in the range of 0.165 to 0.175 mm.