I used the one quarter inch bit to drill forty eight holes in some one eighth inch thick steel. The bit worked well. I The holes are all clean, and smooth. These bits are a good buy. The coating seems to keep the bit from getting too hot, and dull.
I used two of these drills to put holes in mild steel. The 3/16" drill seemed to work well, the 3/8" drill would not. This drill appeared to have been sharpened incorrectly so that the shoulder formed by the making of the pilot tip rubbed but would not cut. I was unable to make a hole with this drill.
35 years in mechanical and design trades so I don’t say this lightly. First bit out of the box wouldn’t cut through 22 gauge steel without applying a lot of pressure. Also the titanium coating peeled away from the bit as I drilled the second hole.