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couple quick tips to make things much a lot easier, and less expensive (and much less time consuming)

besides running your drill at the slowest possible speed that will still cut the steel, and using some type of oil ( cutting oil ) to dissipate heat aand lubricate the contact points - really only three things to consider when you tackle a job that has you boring holes in hardened steel..

three things to know:

punch to mark your spot
drill a smaller 'guide' hole with a bit thats maybe 1/3 the diameter of the bit to follow it
and.. how to correctly sharpen your drill bits


1. spring loaded punch

for years and years i used an old fashioned punch and hammer to mark the spot and have a guide to get the hole started..
first time i used a spring loaded punch i was sold.. push down - and gA-bOiNg!

i think i spent like $10 bucks at harbor freight for the one i use
worth its weight in gold when you have lots of holes to bore in steel..

2. guide holes ( smaller bit )

use a drill bit thats maybe 1/3 the size of the final hole you want to bore. that smaller bit will cut so much faster, save you a lot of time and wear and tear on your bigger bit.. boring two holes faster than boring one big one ?

YES. and it makes the job a hell off a lot easier.. by having a guide hole , the fat tip of the bigger drill bit will have to worm its way through less material as it follows the hole you already drilled - with the cutting edges on the sides of the bigger drill bit being able to do their job without waiting on the center of the bit to worm its way through the metal first...


3. sharpening your metal bits

most manufacturers and machinist will recommend sharpening your metal boring bits after only half dozen holes being drilled - or less!

when a quality metal drill bit is pretty costly ( $20+ dollars for quality bits in the 7/16 to 1/2 size range where i get my bits)

it would be nuts to keep buying new drill bits when one dulls..

especially since sharpening is not very hard to do..

you need a decent bench top grinder with a flat stone.. you need to have a new, flat grinding wheel -
or you can use a " wheel dresser" to pull a nice shape from an old stone

check the factory edges of your drill bit at the very tip ( you dont ever need to sharpen the sides of the bit - just the very tip)

now.. just try to follow the grade of the factory edges, in effect just touching the factory edges up so they are crisp and sharp again..

depending on the hardness of the steel im drilling, ive seen bits thaat were perfectly sharpened ( or brand spankin' new ) dulled after only drilling 2 holes! using dull bits generates way too much heat - and can ruin the integrity of the drill bit in one atteempteed hole with all the heat it will generate..

after some practice, you can dress the cutting edges of a metal boring bit on your bench grinder in just a couple seconds.. when you get to thaat point - a set of quality metal bits can last a life time..


i really liked this thread... and i just thought that some info here might help any folks reading this thread who might be considering tackling somthing like this without any real experience boring hardened steel.. hope it helps somebody, Al