The E-Z LOK threaded inserts kit for metal is a 46-piece set of solid, heavy wall, carbon steel, self-locking, unified coarse thread inserts for use in metal, packaged in a case with a compartment for each of five different sizes: 10-24, 1/4-20, 5/16-18, 3/8-16, and 1/2-13. These inserts are self-locking, with pre-applied Loctite on the external threads that is ready to use in 3-5 minutes and seals against liquids and gases to 6,000 psi when fully cured (72 hours after installation). They fit holes made with standard drill and tap tools, and install with a flathead screwdriver or bolt and jam nut (installation hardware sold separately). The inserts are made of American Iron and Steel Institute (AISI) 12L14 carbon steel, which is cold drawn for better tolerance and strength than hot rolled steel. This steel has a Rockwell hardness of B84 and an ultimate tensile strength of 78,300 psi.
| Quantity of Inserts | Insert Part Number | Internal Thread | External Thread | Length | Tap Drill Size | Tap Size | Min. Full Thread Depth |
| 10 | 329-3 | 10-24 | 3/8-16 | 0.406 | 5/16 | 3/8-16 | 15/32 |
| 10 | 329-4 | 1/4-20 | 7/16-14 | 0.437 | 23/64 | 7/16-14 | 1/2 |
| 10 | 329-5 | 5/16-18 | 1/2-13 | 0.484 | 27/64 | 1/2-13 | 9/16 |
| 10 | 329-6 | 3/8-16 | 9/16-12 | 0.515 | 31/64 | 9/16-12 | 19/32 |
| 6 | 329-8 | 1/2-13 | 3/4-10 | 0.656 | 21/32 | 3/4-10 | 3/4 |
Externally threaded inserts are used to repair a hole with stripped threads, or to install a new threaded hole. The hole must be tapped to the correct size, then the insert is installed; it is anchored by an adhesive or locking elements.
E-Z Lok manufactures threaded inserts for use with metal, plastic, and wood. The company, founded in 1956, is headquartered in Gardena, CA.
