1These self tapping thread inserts can be installed directly and do not need you to tap a thread first 2They are used in low strength materials such as aluminum, magnesium, can avoid thread damage and get a good connection performance, to enhance connection strength and improve connection condition 3Used for parts that requires frequent removing, it can greatly improve service life and wear-resistance of screw thread 4It can prevent screw from getting loose, especially used for products requiring high coefficient of insurance 5Easy 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 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, magnesium, 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