30Pcs Metric Thread Repair Insert Kit M5 M6 M8 Helicoil Car Pro Coil Tool Drilling - clear the damaged threads with a standard drill. (to repair a spark plug thread no pre-drilling is necessary if using the special spark plug tap), please pay attention that for fluteless taps bigger holes are required. Checking - check that the thread and pitch of the tap and the bolt match. Tapping - use the special taps for cutting the holding thread into the cleared hole (recommended to use a suitable cutting oil). Install the insert - place insert on installation tool and position the adjustable ring so that the insert tang is centered in the tang slot. Wind the insert in with a light downward pressure until a half turn below the surface. Don't work against the thread direction as the tang could break. Tang removal - After finishing lift the installation tool and use the tang break tool to remove the tang. For bigger sizes and spark plug taps use long nose pliers to remove the tang. Due to the narrow and exact tolerances the new thread normally is stronger than the original ones. Features: Manufactured from precision stainless steel wire for strength, wearproof and durability. Increase connection strength and fatigue resistance due to the elasticity of wire thread inserts. The Kit Set not only includes the wire thread inserts, but the twist drill bits, wrench, thread taps, breaking pin tool which can solve your most repair needs. Great choice for restoring damaged threads in steel, iron, aluminum and anywhere which metal threads become stripped, crossed or damaged. Instructions: 1.Drill out damaged thread using correctly sized drill bit(supplied). 2.Tap re-drilled hole using tap supplied. 3.Load coiled insert into applicator. 4.Screw coil into casting. 5.Using lug breaking tool, break off tag on insert. 6.Thread is repaired and ready to use. Package Included: 25 x Thread inserts 1 x Lug breaking tool 1 x Installation tool 1 x wrench 1 x Thread tap 1 x Drill bit