dont know what some of you do--heilcoils work, and so do keenserts. but i is---cheap!!!! 
so, i drill the hole oversize, to whatever tap is going to be used. i have used 1/4, 5/16, 3/8, 7/16, and yes, even 1/2 inch ready bolt or what some call all thread--why?? cause its soft, yet way harder than mag or aluminum---and easier to tap. today, i had a 5m/m X 8 hole ate out. i used 5/16 coarse ready rod. as 1/4 would have had too thin a wall after drilling and tapping.after drilling and tapping for the 5/16--i used RED locktite in the threaded hole, and on the all thread, then screwed it in till flush on one side. i waited one day for the locktite to harden, then cut it flush with a hacksaw. u can use a die grinder with cutting disc--but the heat loosens the locktite. so if you do this--a bit at a time, or keep cooling with water. then drill out that slug, and tap for the size bolt it should be. aint likely youll ever pull out the steel slug!!! i could have used 1/4, but like i said, the wall would have been thin, but sometimes you dont have a lot of wall thickness to put the slug into either. i also used this on a bar stud that had got knocked when the tree rolled on the saw!!!! still working fine!!! and that hole ended up off center because of the way the shoulder broke where the stud went into--but after the slug was in and drilled--good to go--use the bar cover in this instance to make sure the hole will be in the center.hope this helps someone, and you dont need a lathe or other expensive machine tool to do this
so, i drill the hole oversize, to whatever tap is going to be used. i have used 1/4, 5/16, 3/8, 7/16, and yes, even 1/2 inch ready bolt or what some call all thread--why?? cause its soft, yet way harder than mag or aluminum---and easier to tap. today, i had a 5m/m X 8 hole ate out. i used 5/16 coarse ready rod. as 1/4 would have had too thin a wall after drilling and tapping.after drilling and tapping for the 5/16--i used RED locktite in the threaded hole, and on the all thread, then screwed it in till flush on one side. i waited one day for the locktite to harden, then cut it flush with a hacksaw. u can use a die grinder with cutting disc--but the heat loosens the locktite. so if you do this--a bit at a time, or keep cooling with water. then drill out that slug, and tap for the size bolt it should be. aint likely youll ever pull out the steel slug!!! i could have used 1/4, but like i said, the wall would have been thin, but sometimes you dont have a lot of wall thickness to put the slug into either. i also used this on a bar stud that had got knocked when the tree rolled on the saw!!!! still working fine!!! and that hole ended up off center because of the way the shoulder broke where the stud went into--but after the slug was in and drilled--good to go--use the bar cover in this instance to make sure the hole will be in the center.hope this helps someone, and you dont need a lathe or other expensive machine tool to do this
