These bits and holder have a specially constructed shank that takes up excess torque to increase their durability and help reduce the chances of cam-out or screw breakage. Rather than a hexagonal cross section for the full length, the shank has a reduced-diameter round portion that is annealed after hardening, making it slightly elastic. This permits a controlled amount of twist, similar to a torsion spring in a vehicle’s suspension. Though barely perceptible to the user, this absorbs energy from the drive tip to cushion damaging loads.
The BiTorsion holder and bits function together. The torsion spring of the holder absorbs lower amounts of torque until its limit is reached, at which point the bit’s torsion zone comes into play, absorbing the peak load as the screw seats.
The 80mm long holder has a free-spinning sleeve you can grasp for steadying a screw, and a grooved shank to fit quick-change as well as regular chucks. Bits lock into the holder with a light push; slide the locking sleeve forward and the bit pops up, where it is held by a magnet, ready for removal. Though developed for the BiTorsion bits, it cushions low to moderate amounts of torque with any plain- or grooved-shank 1/4" hex bit.
The 50mm BiTorsion bits have grooved 1/4" hex shanks and are offered individually or as a set of all six. Also available is a set that includes the holder plus an assortment of 25mm long bits (5.5mm & 6.5mm slot, plus two each of #1 & #2 Phillips) with a fine diamond-grit tip coating to increase friction in the screw recess. This set comes in a compact foldout case.
The Impaktor bits withstand the high torque and percussive action of impact drivers. To maximize durability, various alloys and hardness specifications are used, depending on the drive pattern or size. A layer of fine diamond particles increases friction in the screw recess. Bits are 50mm long and have grooved 1/4" hex shanks for use in the quick-release chuck of most impact drivers. Offered individually.