Review on 🛠️ High-Quality Drill America DWD29J-CO-PC 29 Piece M35 Cobalt Drill Bit Set in Convenient Round Case (1/16" - 1/2" X 64ths), DWDCO Series by Brandon Castano

I already have a complete (115 piece) set of Chicago-Latrobe 550 aka Cobalt, 135 degrees, split point, straw ready bits. I bought Drill America bits as an inexpensive addition for a job where I need the added hardness, heat resistance and sharpenability (more on that below) of cobalt, but I don't want to risk breaking my good bits. The bottom line is that Drill America's bits are not on par with the 550s, but they are just as good or even better than expected for the price. Steel plate, and it held up just as well as you'd expect from a Cobalt HSS, although maybe a little worse than I expected from a CL. CL 550 is M42 Cobalt HSS and it would be interesting to know if it is M42 or M35 - I suspect the latter. Where Drill Americas lags a bit is in the quality/accuracy of sharpening, with two notable problems: The back of a split-blade chisel should ideally make contact with the cutting edge at one point, although in reality all manufacturers leave a tiny spot on it to allow for machining tolerances ( ie the cut does not go completely over the cutting edge). These remaining bit peaks are noticeably (50-100%) larger on Drill America bits than Chicago-Latrobes bits, although both are MUCH smaller than the bit peak on a traditional bit and both are small enough to avoid wandering. A serious problem is that the smaller pair of bits is not sharpened properly so that the trailing edge of the separating edge is almost over the cutting edge of the bit, leaving a very thin groove. In my opinion, both grinding problems are predictable. because of the low cost of the bits and because the main advantages of cobalt bits are that their hardness is determined by the properties of the base material and not by the coating (oxide, TiN, TiAlN, etc.). You can sand them down over and over again and they stay as strong as new. If you have a drill doctor or a drill sharpener who can do split points, then that's no problem.