Brok (en) stuff

Hawaii; I started to drill mine out for bigger bolts and busted the tap from getting over zealous.I still yet have to get down to the store and purchase a masonry bit to drill it out. I was about to do a 3/8 bolt to attach it all together. I forget the thread count. 18? Not sure. But I figure a 3/8 x 18 bolt would be strong enuff.