I need to drill 30 odd 4.5mm holes in a stainless steel pipe; I'm
drilling a small pilot hole ~ 1mm first . Usual type blunt too quickly
4 holes ! Pipe wall thickness is only 1mm and I thought I'd get away
with it.

Carbide tipped and cobalt seem to be recommended . Will tile drills do ?

Any experience or advice ?

Brian
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Brian Howie