Rockmount Threaded Insert Kit Standard Fractional Sizes - 50 Piece Kit Rockmount Threaded Inserts are a fast and inexpensive way to solve all your stripped thread needs. Threaded inserts are cylindrical, metal bushings with features on the outside that anchor them into a plastic or metal base material. They provide high-quality, permanent, wear-resistant internal threads and are designed to be installed in molded or drilled holes in one simple step. With Rockmount Inserts, stripped-thread problems can be corrected in minutes with no special tools or procedures. Save time, money and aggravation by simply drilling a new hole and screwing in the self-tapping, case hardened insert. Download Product Info Sheet Features: Greater clamping pressure in softer materials, provides higher strength, and better seals. Highly Resistant To Pull-Out Effective In High Vibration Applications Self Tapping / Self-Locking Permanent, Wear-Resistant Threads Salvage or Repair Expensive Castings and Moldings Easy To Install In A Drilled or Molded Hole Available In Two Wall Thickness: Standard and Thin Can Be Used In All Metals and Plastics Kit includes 5 of each below: Size (in.) Part No. 1/4-20 90406 1/4-28 90407 5/16-18 90408 5/16-24 90409 3/8-16 90410 3/8-24 90411 7/16-14 90375 7/16-20 90413 1/2-13 90414 1/2-20 90415