I am in desperate need of advice regarding drilling a concrete floor. My all singing all, dancing American made tube bender eventually arrived after being held at Customs for nearly a month, and I now need to get it fixed to the floor. The fixings that I am using are 10 mm diameter floor bolts that require a 16 mm diameter hole X 90 mm deep drilling in the floor .... .... .... I am using a standard 1/2 chuck percussion drill, and all I am doing is burning out the drill bits. ... and so far I've not achieved to drill one full hole for a bolt. I have considered hiring a "wet" diamond core drilling machine, but none of the local hire companies seem to have 16 mm diamond core bits available. If needs be I can increase the size of the bolts up to either 12 mm or 16 mm dia bolts, and I know that a 12 mm bolt requires a 20 mm drill bit, but I am unsure about the 16 mm dia bolts. Any advice about drilling concrete and installing floor bolts will be greatly received, as I must have this tube bender bolted down and in use as soon as possible due to the appalling delay caused by the Customs and Revenue service eating into my production and delivery schedules.