US Patent 10077858 Anti-rotation key for threaded connectors

A tubular member connection system includes a pin having a central axis, external pin threads, and an annular pin lip at a shoulder surface of the pin. A box has internal box threads and an annular box lip at an end surface of the box. The box threads are shaped to mate with the pin threads to releasably secure the pin to the box. A pin recess is formed in an outer diameter surface of the pin, the pin recess extending in an axial direction from the pin lip. A pin key is selectively fastenable within the pin recess, the pin key having pin teeth on an outer edge of the pin key. The box teeth are located in the box. The box teeth selectively mate with the pin teeth and resist rotation of the pin relative to the box.