An interlocking thread with a tooth-cross-section that is wider at its crest than at its root and with V angles located both along the crest and the root which tightens into a tapped hole that has a similar thread cross-section.

Provided is a manufacturing method for a compound screw having a first thread groove and a second thread groove with a different lead angle or lead direction from the first thread groove, wherein at least a portion of the first thread groove is formed by feeding a threading tool that acts on a workpiece a first feed amount toward the workpiece, the workpiece being a rotating object to be machined. Additionally, at least a portion of the second thread groove is formed by feeding the threading tool that acts on the workpiece a second feed amount that differs from the first feed amount. With these steps, a compound thread portion is formed in the workpiece. As a result, it is possible to mass produce a compound screw having two thread structures of differing lead angles and/or lead directions with a high level of quality.

An interlocking thread with a tooth-cross-section that is wider at its crest than at its root and with V angles located both along the crest and the root which tightens into a tapped hole that has a similar thread cross-section.

A process of forming a fastener with improved threading to resist multi-axial forces and off-axis loading scenarios is provided. The process may include placing first and second mill tools adjacent a shaft of the fastener having a proximal end and a distal end, rotating the shaft and the first and second mill tools, and translating the first and second mill tools along at least part of a length of the shaft to form: a first concave undercut surface oriented toward the proximal end, a first convex undercut surface oriented toward the distal end, a second concave undercut surface oriented toward the distal end, and a second convex undercut surface oriented toward the proximal end.

An interlocking thread with a tooth-cross-section that is wider at its crest than at its root and with V angles located both along the crest and the root which tightens into a tapped hole that has a similar thread cross-section.

A method for producing a thread can include a) generating a number n1 of twisted grooves in a wall of the workpiece encircling a thread axis (M) or generating a wall of the workpiece which has a number n1 of twisted grooves and encircles a thread axis, b) respectively inserting a thread generating region of a tool into each of the twisted grooves in a twisted insertion movement, c) generating a thread in each wall sub-region, adjoining the groove(s), of the wall of the workpiece by rotating the tool about the thread axis (M) and with a simultaneous axial feed motion of the tool coaxially with respect to the thread axis with a particular axial feed speed and d) moving each thread generating region of the tool out of the associated groove in a twisted removal movement matched to the twisting of the associated twisted groove.