Patent ID: 7402109

Claim:
A method for making a thread-forming tapping screw having a head, a shaft extending from the head and a helical thread on the shaft, said method comprising steps of: determining a screw size and a mean minor diameter for the screw as the average of minimum and maximum acceptable shaft diameters for the screw size; forming the screw head, the shaft extending from the head and a tapered end on the shaft having a distal tip, the distal tip being created with a rounded shape; forming the helical thread on the shaft including a thread start on the tapered end and a first full thread following the thread start; and said forming steps including at least one of: creating the thread start at a position on the tapered end an axial distance from the distal tip related to the mean minor diameter by a thread start factor of between about 0.4 and about 0.5; creating the first full thread on the shaft an axial distance from the distal tip related to the mean minor diameter by a distance factor of between about 1.02 and about 1.08; creating the tapered end with a diameter at the thread start related to the mean minor diameter by a diameter factor of between about 0.6 and about 0.7; and creating the distal tip with a rounded shape formed on a radius related to the mean minor diameter by a radius factor of between about 0.2 and about 0.3.