Abstract: A chuck comprises: a chuck body attached to a spindle of a machine tool; master jaws attached to the chuck body along the normal of the chuck body and formed with T-shaped grooves extending along the length thereof; T nuts having tops and trunks, the tops being slidably fitted in the T-shaped grooves of the master jaws; gripping claws having work holding surfaces and grooves for engagement with the trunks of the T nuts; and eccentric shafts inserted into holes formed across the T nuts and the gripping claws and used for attaching the gripping claws to the T nuts. The holes extend across the T nuts and the gripping claws which are engaged with one another. The gripping claws have large reshaping margins at work holding surfaces thereof.

Abstract: A chuck comprises: a chuck body attached to a spindle of a machine tool; master jaws attached to the chuck body along the normal of the chuck body and formed with T-shaped grooves extending along the length thereof; T nuts having tops and trunks, the tops being slidably fitted in the T-shaped grooves of the master jaws; gripping claws having work holding surfaces and grooves for engagement with the trunks of the T nuts; and eccentric shafts inserted into holes formed across the T nuts and the gripping claws and used for attaching the gripping claws to the T nuts. The holes extend across the T nuts and the gripping claws which are engaged with one another. The gripping claws have large reshaping margins at work holding surfaces thereof.