Chain saw

A motorized chainsaw (10) with a housing (12), a sprocket (22) mounted thereon, and a blade (14) aligned with the sprocket, which blade protrudes beyond the housing (12) and guides a saw chain (16) engaged with the sprocket (22) in a revolving manner, where the blade (14) is mounted such that it is adjustable by means of longitudinal displacement in relation to an element selected from the group consisting of the housing (12) and the sprocket (22) by means of a chain tensioning device (28) and where the chain tensioning device (28) has a stop (32) that is fixable to the blade (14) and a cam (30) that is rotatable by means of a rotational member (36, 38), characterized in that the cam (30) is lockable in a form-fitting and non-rotational manner in relation to the housing (12) by means of the rotational member (36, 38), that the rotational member (36, 38) is comprised of two handwheels that nest one inside the other as an inner and outer handwheel and rotatable in relation to one another around a common axis, that the inner handwheel (38) is movable axially in relation to the housing (12) and is supported on the blade (14), and that the outer handwheel (36) is coupled to the cam (30) in a rotary driving manner.