HSS Jobber Drills

This is the most common length and type of drill bit, used far and wide across many engineering industries.
High Speed Steel is a form of tool steel; HSS bits are hard, and much more resistant to heat than high carbon steel. They can be used to drill metal, hardwood, and most other materials at greater cutting speeds than carbon steel bits, and have largely replaced carbon steels.

The length of the flutes is between nine and fourteen times the diameter of the drill, depending on the drill size. So a 12" (12.7 mm) diameter drill will be able to drill a hole 4 12" (114.3 mm) deep since it is nine times the diameter in length. A 18" (3.2 mm) diameter drill can drill a hole 1 58" (41.3 mm) deep since it is thirteen times the diameter in flute length