A fastening tool comprising: a housing; a nosepiece assembly connected to the housing, the nosepiece assembly including a nose portion having a longitudinal body, a door slidably connected to the nose portion by a door plate, the door being biased toward the housing, and a fastener drive track defined between the door and the nose portion; a magazine assembly for feeding fasteners successively to the fastener drive track of the nosepiece assembly; an engine carried by the housing and configured to drive a fastener along a drive axis out of the fastener drive track and into a workpiece through successive operating cycles each including a drive stroke and a return stroke; and a depth adjustment mechanism mounted on the door, the depth adjustment mechanism including: a depth adjustment wheel rotatable about a central axis that extends through the depth adjustment wheel and having an inner surface with a threaded section adjacent to an unthreaded section along the central axis; and an adjustment screw extending through the depth adjustment wheel and operatively engaging the door plate, the adjustment screw having a head portion and a shank portion that includes a threaded part that engages the threaded section of the depth adjustment wheel, so that a rotational movement of the depth adjustment wheel effects a relative axial movement of the adjustment screw and longitudinal movement of the door with respect to the nose to increase and decrease the depth that a fastener is driven into a workpiece. a housing; a nosepiece assembly connected to the housing, the nosepiece assembly including a nose portion having a longitudinal body, a door slidably connected to the nose portion by a door plate, the door being biased toward the housing, and a fastener drive track defined between the door and the nose portion; a magazine assembly for feeding fasteners successively to the fastener drive track of the nosepiece assembly; an engine carried by the housing and configured to drive a fastener along a drive axis out of the fastener drive track and into a workpiece through successive operating cycles each including a drive stroke and a return stroke; and a depth adjustment mechanism mounted on the door, the depth adjustment mechanism including: a depth adjustment wheel rotatable about a central axis that extends through the depth adjustment wheel and having an inner surface with a threaded section adjacent to an unthreaded section along the central axis; and an adjustment screw extending through the depth adjustment wheel and operatively engaging the door plate, the adjustment screw having a head portion and a shank portion that includes a threaded part that engages the threaded section of the depth adjustment wheel, so that a rotational movement of the depth adjustment wheel effects a relative axial movement of the adjustment screw and longitudinal movement of the door with respect to the nose to increase and decrease the depth that a fastener is driven into a workpiece. a depth adjustment wheel rotatable about a central axis that extends through the depth adjustment wheel and having an inner surface with a threaded section adjacent to an unthreaded section along the central axis; and an adjustment screw extending through the depth adjustment wheel and operatively engaging the door plate, the adjustment screw having a head portion and a shank portion that includes a threaded part that engages the threaded section of the depth adjustment wheel, so that a rotational movement of the depth adjustment wheel effects a relative axial movement of the adjustment screw and longitudinal movement of the door with respect to the nose to increase and decrease the depth that a fastener is driven into a workpiece.