The present invention relates to a clamp of a jig fixing that service life improvements and is arranged so that that for fixing firmly the position of the material in order to facilitate the threading in the material, and the lower clamp material is placed on top, wherein in the jig for fixing clamp consisting of a material placed in the lower clamp to upper clamp to press the fixed,
First replacement protrusions and, the first is inserted into the first replace home support contacting a material that is placed in the lower clamp, a first replacement on the upper surface of the two sides respectively of the lower clamp are formed to extend in the longitudinal direction of the lower clamping groove; and a second replacement groove on a lower respective sides of the upper clamp are formed to extend in the longitudinal direction of the upper clamp; and, wherein the second replacement is inserted into the home location of the material by pressure contact to the material that is placed in the lower clamp second replace the projection to secure the; and is formed at least one on each of the upper two sides and the bottom sides of the upper clamp of the bottom clamping a first replacement means for coupling the position of the replaceable projection on or off the coupling; something in as it characterized by,
If in the process of replacing the projection formed on the lower clamp and the upper clamp, which firmly placed to secure the material to be threaded fixing hardening by ganpyeonhi present a structure that can be replaced, the material is lower, and the replacement of the upper clamp projections damage and breakage ganpyeonhi to be reused by replacing the projection there is an effect that allows to extend the useful life of the device.
Moreover, as a replacement protrusion formed on the lower and upper clamp having a structure in which the individual separated, it is in contact with the material and directly formed from a material having excellent strength but replacing the projection is exposed to the rotating force by the damage and breakage rate of replacing the projection reduction by an effect that can be induced to the maintenance of the apparatus easier to.