Straight shank expansion reamers mount to the chuck of a drill press or similar machining tool. Use them to enlarge or finish an existing hole to a precise tolerance or size. An adjustment screw on the reamer expands the size of the cutting head so it can be reground to its original size, which extends the life of the reamer by allowing the operator to compensate for wear on the reamer's cutting edge.

These reamers have a Morse taper shank that inserts directly into the spindle of a compatible tool or into an adapter such as a Morse taper sleeve or socket. This maximizes efficiency when installing and removing the reamers. Morse taper shank reamers provide accurate centering. They are self-locking, which means they are held in place by the friction between the shank and the toolholder. Expansion reamers are used to enlarge or finish an existing hole to a precise tolerance or size. They have an adjustment screw that expands the size of the cutting head so it can be reground to its original size. This extends the life of the tool by allowing the operator to compensate for wear on the reamer's cutting edge.