Designed for drilling in extremely hard materials, including stainless steel. Cobalt drill bits have a great resistance to heat and friction providing a longer tool life. Century 135 degree quick-cut points are self-centering and penetrate faster with less pressure. Cobalt drill bits offer 14 times Life Rating when compared to standard 118 degree point drill bits.
used to drill about 10 rivets and it started to dull. Of course, the rivet metal was very strong. I feel like I've gotten my money's worth and could buy another one.
A quality product is worth it. I had to drill through 1/8 steel and this bit went through with no trouble. I definitely recommend it if you want to do some serious metal drilling.
I only have 1.5 holes in 3/8" cast iron. Tried slow speeds, high speeds, let the drill sit and cool, used it off for 4 days to not to overload him, and got ONLY 1.5 holes with almost no cast iron.Not worth the price.