A tool is used to limit the torque applied to tighten the threaded
connection of prosthesis components placed in skeletal bones, for example
dental implants. The device had a handle, a retaining screw, a single use
torque limiting shear pin and a drive shaft. The handle has a tapered
counter sunk cross bore with left handed threads to allow installation of
a drive shaft which engages a torque limiting shear pin which, in turn,
engages a left hand threaded retaining screw. The drive shaft extends
from the handle to engage any threaded fastener that has a head that
corresponds to the drive shaft end. The drive shaft and the shear zone of
the shear pin are completely isolated within the wrench handle so that
all rotational force is utilized in the actual shearing of the shear pin
to a torque accuracy of .+-.0.3 Ncm, approximately.