Abstract: A tool device in which a torsion tool such as a drill bit is provided with oppositely disposed flanges of such size and shape that the jaws of the chuck press against the sides of the flanges while all three jaws tend to engage and clamp the shank of the tool, so that the chuck may be manually tightened and loosened. Where the jaws of the chuck are not cut away but form a solid cylinder when engaged with each other, the flanges can be of such size and shape to be engaged by two of the jaws while allowing all three jaws to engage the shank of the tool without substantial flexing of the flanges. Where the jaws are cut away so that their clamping portions do not meet when the jaws are brought together, the flanges may be more flexible to ensure that all three jaws engage the shank of the tool.