Multilobular Fastener Modified Trailing Surface Wedging

The patent applies local quality by providing a modified zone only on specific portions of the trailing surfaces rather than uniformly across the entire socket. The modified zone with increased diameter is localized to specific angular positions (e.g., 120 degrees apart in a six-lobular pattern), creating localized wedge engagement points while maintaining a smaller overall socket diameter. This resolves the contradiction by providing torque transfer enhancement only where needed rather than increasing the entire socket diameter.

The modified zone creates localized stability enhancement at specific engagement depths without increasing the overall socket diameter. By concentrating the diameter increase in specific angular regions rather than uniformly, the patent achieves stable wedge engagement at the required depth while maintaining a tighter fit at the socket mouth where the unmodified trailing surfaces provide better alignment.

The patent maintains manufacturing simplicity by applying the modified zone only to specific portions of the trailing surfaces rather than redesigning the entire socket geometry. The modification can be achieved through relatively simple machining or forming operations localized to specific angular positions, preserving most of the original manufacturing process while adding the stability-enhancing feature.