US Patent 8690200 Radially-inserted anti-rotation key for threaded connectors

A pipe connection includes a box that mates with a pin. A box slot extends through a side wall of the box at a point adjacent the rim for alignment with a pin slot formed on the pin. Each of the slots has a circumferential dimension and an axial dimension that is less than the circumferential dimension. The pin slot has a greater circumferential dimension than the box slot. A locking key has a pin section and a box section located within the pin slot and the box slot, respectively, when the key is installed. The pin section has teeth that bite into the pin slot. The key has a width substantially the same as the circumferential dimension of the box slot.