Abstract: A screw clamping apparatus includes a shank and a drive member for exerting a driving force on a shank to screw the same into a bore to exert a clamping force on an article. The shank is provided to shear once a predetermined turning torque from the drive member, and hence clamping force, is achieved and the plane of shear can be accurately determined relative to the surface of the article on which the bore is formed and into which the shank is screwed. This is an advantage over the conventional clamping screw, which is provided to shear at one fixed weakened location and, when sheared, can leave an undesirable protrusion.

Abstract: A screw clamping apparatus includes a shank and a drive member for exerting a driving force on a shank to screw the same into a bore to exert a clamping force on an article. The shank is provided to shear once a predetermined turning torque from the drive member, and hence clamping force, is achieved and the plane of shear can be accurately determined relative to the surface of the article on which the bore is formed and into which the shank is screwed. This is an advantage over the conventional clamping screw which is provided to shear at one fixed weakened location and, when sheared can leave an undesirable protruding portion above the surface of the article. The screw clamping apparatus of this invention allows one size shank to be used for clamping articles to different sizes and the position of the planar shear can be located at a position along the length of the shank, thereby eliminating the occurrence of protrusions when shear occurs.