Igot given a load of small drillbits by a freind who worked at a electronics machine factory (they made
very high tec objects de computation) The one 1.5mm bit he gave me I drilled 20+ holes 9mm deep into a 10mm peice of Cu with a drillpress, when it snapped I brought four others from a toolshop, they all snapped on the first hole!. The moral of the story is "Buy a
quality drillbit" (though 1/4 should be strong 'whatever')...
I'd use a centre/drilpress and vice/hold~down as well, cause it's the sligthest side movement that will 'grab' and snap the bit. Keep it cool with WD40, so it does'nt make the Cu grabby. With a 1/4 drillbit you should be OK unless you do something careless. Use a sharp bit so you don't 'bow' the die (if it's quite a small peice or near to the edge) and apply the pressure gently, let the drill do the work, not your elbow
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