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I was following the chart on my drill press and was using 720 RPM for the 1/4 and 870 for the 1/8, moderate pressure for hand feed, and a constent flow of coolant. Do I need to change my process at all or did I just buy crappy drill bits?

I run mine at 1100 in a press,I seem to recall 1200 was the correct rate for a 3/16's bit.I also seem to remember that they vary by size of bit.

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Thanks for the feedback guys. I was using a drill press with a small XY table, but perhaps I could have tightened the set screws to avoid some play while drilling. Also it seems like my speed was a little low. The drill bits came in one length, I think it was 3-4 inches, I just got some new ones from K&G finishing and I wanted check before mounting them and cracking them as well.

also use as short of a drill as you can ,most steels you dont really need lube with carbide , I tend to use it very lightly if I do

I have had really bad luck with two Carbide drill bits, one was 1/8 the other was 1/4. They both broke on the first hole that I tried drilling with them into annealed L6. (no scale on the surface)

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the work piece has to be clamped securly as virriation will shatter carbide befor hi speed thats the trade off , mor hard less senative to vibrations /chatter and what not

I was following the chart on my drill press and was using 720 RPM for the 1/4 and 870 for the 1/8, moderate pressure for hand feed, and a constent flow of coolant. Do I need to change my process at all or did I just buy crappy drill bits?