Drill bit shank in drills meant to reach into very tight spaces, and threaded countersink cutters are widely used (along with finely adjustable depth stops) to create holes which put a matching rivet directly flush with the surface. Drill bit shank The shank is the end of a drill bit grasped by the chuck of a drill. The cutting edges of the drill bit contact the workpiece, and are connected via the shaft with the shank, which fits into the chuck. In many cases a general-purpose arrangement is used, such as a bit with cylindrical shaft and shank in a three-jaw chuck which
Tightening key Tightening key A corner key or tightening key is a small wedge or block of board, timber or plastic, inserted into the slotted inside corners of a canvas stretcher frame to prevent or adjust sagging. The piece is tapped in to expand the stretcher bars slightly, tensioning the canvas. The keys can be used to re-tighten the canvas as it relaxes naturally over time. Tightening keys are commonly made in plastic or wood, and are commonly known as corner keys or corner wedges. Corner keys or wedges come in various forms. Most are available for a single size stretcher bar,