- Messages
- 21,548
- Location
- Birmingham
Old railway bricks are tough as well did some work at a station years ago good quality masonry drill = 1 hole 50mm deep 6mm dia & 20 minutes with hammer drill, they seemed worse than engineering brick
Worst I've come across was in Bury St Edmunds where they had mixed local flint as ballast when pouring the floor, burnt out a couple of drill bits and had grease running out of the gearbox on the drill it got that hot!.