Features: These self tapping thread inserts can be installed directly and do not need you to tap a thread first. They are used in low strength materials such as aluminum, can avoid thread damage and get a good connection performance, to enhance connection strength and improve connection condition. Used for parts that requires frequent removing, it can greatly improve service life and wear resistance of screw thread. It can prevent screw from getting loose, especially used for products requiring high coefficient of insurance. Easy to maintenance, install a thread insert into a damage screw hole, then the screw hole can be used as normal, in order to avoid workpiece loss. Specifications: Material: Metal Inner Thread Size: M4(diameter) x 0.7(pitch) x 8mm(length) Outer Thread Size: M6.5(diameter) x 0.75(pitch) Drilling Diameter: 5.8~5.9mm(plastic); 6.0~6.1mm(aluminum alloy); 6.1~6.2mm(cast iron) Min. Drilling Depth: 10mm Quantity: 20pcs Weight: 20g(approx.) Package Includes: 20 x Threaded Inserts