Blair Rotabroach Metric Kit 11091 for Metal Drilling

Drilled twenty 1/2" holes in 1/4" steel with my drill press . They worked great and it's still razor sharp after I got done . I don't mean mildly sharp, they are razor sharp like I didn't even use them. I did hit the holes with a squirt of WD40 about every 2 seconds while cutting , and and as I got close to the end of the hole it did bind for a second so I lifted to clear the hole and continued right thru. Likely this was due to the flex in my clamping and small and cheap harber frate drill press. If the cutter slows or stalls, lift it and spray lubricant in to clear the hole and keep the cutter cool. I Have not tried them in a hand drill. I would imagine you'd need an extremely steady hand and then you don't have a free hand to keep spraying oil into the hole. Don't forget to make a take a small hammer and use the center punch to prevent the cutter from wandering...and don't forget to install the spacer washer first !