A few bolts stripped on my block and I need to heli-coil them. The size of the heli-coil thread repair insert is M10x1.5. Does anyone know what size drill bit I need to use to prepair the hole? Any other heli-coil tips would also be appreciated if someone has had luck doing this.

Thanks

 

Most HC kits usually have the recommended drill bit size on it. If you only have the helicoil, maybe go to a parts store and look at their kits to see if they list the drill bit size.

 

I have the heli-coil but there is no drill size on the packaging.

 

From my file, for a M10 X 1.5 tap you need a 8.5 mm drill bit.

GoodLuck.