Abstract: The present invention provides a tap (10) adapted for formation of female screw-threads in a plurality of metal parts. Each female screw-thread is 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 (10) is fluteless and comprises a threaded portion (23) with a triangular form thread (11) with an angle of thread (gamma) in the range 29°-40° and radiussed crests (16). The present invention also relates to a method of using such a tap.

Abstract: With reference to FIG. 3 the present invention relates to a method of manufacture of a product from a first component (4) of deformable material and a second component (5), the method comprising the steps of: inserting a portion of the first component (4) through an aperture predefined in the second component (5); and subsequently deforming the material of the first component (4) to form a pair of spaced apart shoulders (50) integral with the first component (4), the spaced apart shoulders (50) holding therebetween the second component (5) and thereby preventing the second component (5) sliding along the first component (4); wherein: each shoulder (50) is formed by applying tool means (20, 21) to a surface of the first component (4) to create a recess in the surface and to form the shoulder (50) adjacent to the recess with the shoulder (50) being formed by displacement of the deformable material of the first component (4) during the creation of the recess.

Abstract: With reference to FIG. 3 the present invention relates to a method of manufacture of a product from a first component (4) of deformable material and a second component (5), the method comprising the steps of: inserting a portion of the first component (4) through an aperture predefined in the second component (5); and subsequently deforming the material of the first component (4) to form a pair of spaced apart shoulders (50) integral with the first component (4), the spaced apart shoulders (50) holding therebetween the second component (5) and thereby preventing the second component (5) sliding along the first component (4); wherein: each shoulder (50) is formed by applying tool means (20, 21) to a surface of the first component (4) to create a recess in the surface and to form the shoulder (50) adjacent to the recess with the shoulder (50) being formed by displacement of the deformable material of the first component (4) during the creation of the recess.