KEY LOCKING INSERT, SYSTEM OF MEASUREMENT INCH, INSERT DIAMETER 1/2 IN, OVERALL LENGTH 7/16 IN, INTERNAL THREAD SIZE 5/16 IN.-24, INTERNAL THREAD FIT 3B, EXTERNAL THREAD SIZE 1/2 IN.-13, EXTERNAL THREAD FIT 2A, THREAD DIRECTION RIGHT HAND, THREAD TYPE FINE, MATERIAL STAINLESS STEEL, FINISH PLAIN, WALL TYPE HEAVY WALL, NUMBER OF LOCKING KEYS 4, COMPATIBLE MATERIAL METAL, COMPATIBLE TAP SIZE 1/2 IN.-13, DRILL BIT SIZE 29/64 IN, MINIMUM INSTALLATION