A shape memory alloy has a tool holder is disclosed using.
A tool holder using a shape memory alloy is disclosed, of the rear coupling part that is coupled to the chuck means; And forming a bore ssaengkeu additional insertion of a tool therein, an outer circumferential surface formed on a plurality of slits are formed in communication with the bore to be arranged in a circumferential direction and a longitudinal direction, in part of the front male thread portion is formed clamping the leading end of the outer circumferential surface; Holder body consisting of; the engaging portion and the axial shape of the outer circumferential surface between the clamping portion reinforcing part forming a taper shape, a two-dimensional curved shape, any shape of the horizontal type; The clamping portion a plurality of shape-memory alloy which by tightening or loosening the radial direction of the portion clamped by the axial holding heat or cool fitted on the respective slits formed in a longitudinal direction in the ring; A spacer consisting of one or a plurality of middle spacers are interposed between the side spacer is interposed between the reinforcing portion and the shape memory alloy ring the clamping portion, wherein the shape memory alloy ring; And a screw tap formed on the inner circumferential surface by being screwed onto the male screw section the clamping parts of the locking cap to prevent the departure of a shape memory alloy ring; intended to cover.