A device to sense degree of twist in a screwdriver and the magnitude of force applied includes a contacting portion, a deformation portion, a sensing portion, and a processor. The contacting portion receives a grip and twist pressure through the deformation portion which is tiltedly fixed to the contacting portion. The deformation portion carries the sensing portion and elastically deforms under the force and/or the torsion. The sensing portion detects a deformation of the deformation portion and generates a corresponding electrical signal. The processor receives the signal and determines the values of the twist caused and the force applied.