Being a cheapskate I bought a set of bi-metal hole cutters from Aldi for £6 just in case I ever needed them and they have cut holes in aluminium, steel propane bottles and in wood with no problems. I wouldn't compare them to Starret or Bahco but for occasional use they are still going strong.
I can officaly saw the Titan Holesaws are Rubbish, the large abour is broke and they only bearly managed to cut two flanges. I used low speed with not to heavy preasure and lubed with oil to keep it cool.
Going to take them back tomorow and complain, hopefully get my money back.
I just saw this thread and was going to warn you about the titan stuff , definatly screwfixes cheapest and nastiest range apart from forge steel perhaps
titan drill bits really are bad , cheap chinese made crap
the bosch cobalt ones are good esp for stainless (not keen on the quick release arbours tho never last long in my hands !)
the sf own brand are ok .
cheers mike
Personally, id steer clear of the Bosch ones they do aswell. Tried them, unless i had a few bad ones, the saws were quite sloppy on the arbor. Expensive for what they are too.