Description of Chicago Latrobe High Speed Length 15 Piece
Set of 15 short length drill bits includes inch sizes 1/16" through 1/2" in 1/32" increments. High-speed steel (HSS) provides hardness for wear resistance. Black oxide finish reduces wear while promoting chip and coolant flow on ferrous materials. Self-centering 135-degree split point penetrates hard material without a pilot hole and produces small chips to reduce clogging. Extra thick web for increased strength and rigidity compared to standard drill bits. Made in the USA.
Through trial and error I found that this set can handle a wide variety of materials and applications .The bits are made to last and don't dull easily..