Drilling through steel

cianoc07

Hi i want to drill through steel that is located above a window ope. The bits im using are 5.5mm hilti. Now its next to impossible to get through it. I dont see any progress. i tried drilling at slow revolution but still nothing. are these bits use 4 or five times then no good? or am i doing it wrong

aujopimur

Are you using steel drills?, Hilty drills are usually for masonary.

cianoc07

yeah of course..as mentioned above hilti drill bits for steel

Alun

Yes, Hilti make HSS bits for drilling steel too.

micko4

Is it stainless steel or something? Try a cobalt or titanium bit..how big is the hole you need? If its big start with a small one like a pilot hole then go bigger..keep a little container of water or coolant beside you and dip the bit in every few seconds to keep it cool..once it over heats the bits no use.

kieran.

Ideally you want to using a Magnetic drill or similar !

ART6

Use a cobalt drill and lubricate the tip with 3-in-1 oil and apply a lot of pressure to start the cut. Steel lintels tend to have a hard mill scale coating that you need to break through to get into the steel.

2 stroke

If you have drilled through and hit concrete, your bit is ****ed.
Others mention lubricating the drill tip, not realy practical when drilling upwards through plaster into steel.
With a new bit, use low speed, or start/stop drilling to reduce heat buildup. Try to gauge the depth of steel or time it takes to drill through. Then stop drilling before breakthrough, and use a masonary bit with hammer action to punch through into concrete