1、These self tapping thread inserts can be installed directly and do not need you to tap a thread first. 2、They are used in low strength materials, can avoid thread damage and get a good connection performance, to enhance connection strength and improve connection. 3、Used for parts that requires frequent removing, it can greatly improve service life and wear-resistance of screw thread. 4、It can prevent screw from getting loose, especially used for products requiring high coefficient of insurance. 5、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. Steel thread inserts can effectively improve screw connection, greatly improving the reliability. Used in all kinds of low strength materials, thread inserts can largely improve the wear resistance performance of screw connection, and avoid thread damage. 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, can avoid thread damage and get a good connection performance, to enhance connection strength and improve connection. 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. Specification: Product Model: 308 type Material: Zinc plated carbon steel N.O.(Optional) Inner Size Outer Size Length(mm) Drilling Diameter(mm) Min. Drilling Depth(mm) Quantity Weight Aluminum Alloy Cast Iron #1 M3*0.5 M5*0.6 6 4.6-4.7 4.7-4.8 8 10pcs 6g / 0.2oz #2 M4*0.7 M6.5*0.8 8 6.0-6.1 6.1-6.2 10 10pcs 11g / 0.4oz #3 M5*0.8 M8*1.0 10 7.4-7.5 7.6-7.7 13 10pcs 19g / 0.7oz #4 M6*1.0 M10*1.25 12 9.3-9.4 9.5-9.6 15 10pcs 38g / 1.3oz #5 M8*1.25 M12*1.5 14 11.1-11.3 11.3-11.5 18 10pcs 54g / 1.9oz #6 M10*1.5 M14*1.5 18 13.1-13.3 13.3-13.5 22 10pcs 87g / 3.1oz #7 M12*1.75 M16*1.75 22 15.0-15.3 15.3-15.5 26 10pcs 114g / 4oz #8 M14*2.0 M18*2.0 24 17.0-17.2 17.3-17.5 28 10pcs 150g / 5.3oz #9 M16*2.0 M20*2.0 24 19.0-19.2 19.3-19.5 27 10pcs 172g / 6.1oz Package list: 10 * Threaded Inserts