Review on IRWIN 29-Piece Titanium Nitride Coated Tool Set (3018003) by Ricardo Ware

I've been a long time fan of Irwin TurboMax drill bits. They offer ever faster speed, easier drilling, no walking in almost every material found in life except stone and ceramics. When you order these drills, please note the following fact: These drills have 4 cutting edges instead of 2 like conventional drills, so they require more torque but less speed. So if you use an AC powered drill, which typically has a higher RPM but lower torque, then these drills are not for you. Or, if your AC drill has mechanical shifting, set it to the lowest speed available. The optimal speed for these drills is around 1000 rpm, for larger diameters even 300-400 rpm. Of course it works at higher speeds, but the bits will dull much faster or even break off at the tip. Also note, YOU CANNOT SHARPEN THEM, no matter what the various drill sharpener manufacturers say!