There are eight 341SD reduced shank drills in 341SDSET, with a 1/2 inch parallel shank for all drilling diameters, meaning even the larger drilling diameters can be held in conventional hand-held power tools used by maintenance and repair professionals. The 341SD drills are manufactured from High Speed Steel for drilling in many materials including stainless steel, steels and aluminum, with a 118 degree conventional point to provide strength and make them easy to regrind so the drills can be used many times over. 341SD drills have a steam oxide finish which prevents workpiece material from sticking to the cutting surfaces of the drill so you get clean and accurate holes.