Carr Lane heavy duty key inserts are general-purpose threaded inserts with a thick, heavy-duty thread wall, suitable for most applications. Heavy-duty Key Inserts are ideal for thread reinforcement, especially when the mating stud or bolt will be removed frequently. They provide strong, permanent steel threads in almost any parent material – ferrous, non-ferrous, or non-metallic. Heavy-duty Key Inserts are also well suited for quick repair of stripped, damaged, or worn threads. Locking keys positively prevent the insert from rotating. Browse the complete line of heavy duty key inserts from Carr Lane in our online catalog.