Devices are described relating to the retaining of surgical tools (200, 300, 400, 420) within the chuck (102) of a reciprocating surgical instrument (10), such as a reciprocating saw. A securing chuck is disclosed for securing a surgical tool to a reciprocating surgical instrument that comprises a shaft (104) and a securing member (146). The shaft defines an axis (L) and has a cylindrical bore (110) extending along the axis. The bore may be shaped to receive a substantially rounded tool shank. A pair of transverse slots (112) may extend into the shaft along a plane passing through the axis for receiving a substantially flattened tool shank. The transverse slots intersect with the cylindrical bore. The securing member is carried by the shaft and is radially movable relative to the bore both inwardly and outwardly to secure the surgical tool in the chuck.
