cranck case problems

[JohnD]

I had to remove a broken stud from a block, and i tried to weld a nut on with no success and i found online [possibly on here] that a diamond tipped tile core drill can be used to "core out" the tap and not interfear with the surrounding metalwork 

Iam sure it was a dewalt branded one i used, but cannot remember the size, but this is the type of drill bit used

 https://www.screwfix.com/p/erbauer-diamo...lsrc=aw.ds