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  • Trying to drill a few holes in some hardened (?) steel plate but having some trouble. First hole went fine, punched it, pilot hole then stepped up to final size. For the second one for some reason the bit just won't remove any material. Got a dimple, but the bit just spins, spins and spins. Snapped a few bits, bought a fancy cobalt bit set, still can't get through it.

    Can anyone offer some wisdom as to what I'm doing wrong? For reference, its a 3 mm plate, the foot pedal on a workbench castor. Combi drill on low speed.

  • Yeah I did dull the first bit but even newer fancy cobalt bits are not working. Would try cutting fluid if I had some- will give chain lube a go.

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