Carr Lane key-locking threaded inserts are ideal for thread reinforcement, especially when the mating stud or bolt will be removed frequently. They provide strong, permanent steel threads in a weaker parent material — ferrous, non-ferrous, or non-metallic. Key Inserts are also well suited for quick repair of stripped, damaged, or worn threads. A solid version is also available to use as a handy plug to relocate holes drilled or tapped on the wrong location. Install with standard drills and taps. Important: Use tap drill specified in table (slightly larger than standard for that thread size). Tap-drill hole tolerance should be -.001/+.004 (-.001/+.005 above .500 dia).
Locking keys are driven down into the parent material during installation, providing a positive mechanical lock against rotation. Inserts with an ID thread 5/16 and above have four locking keys, smaller sizes have two. Pull-out strength can be calculated approximately by the following formula:
Key Inserts are often used to reinforce tapped holes in aluminum tooling plates.