Blade holder for assembling a replaceable blade

A blade holder for assembling a replaceable blade, the replaceable blade comprising a long assembling hole, the long assembling hole comprising a wide hole section and a narrow hole section communicating with the wide hole section and being close to a blade point, the blade holder comprising:

• a supporting base assembled with a shank and provided for a heel of the replaceable blade to dispose thereon;
• a mounting rod integrally extended from the supporting base and capable of being placed in the wide hole section, the mounting rod comprising an assembling rail disposed at one end opposite to the supporting base and a first mounting hole, wherein the assembling rail is engaged with the narrow hole section when the replaceable blade is assembled in a direction toward the supporting base;
• and
• a blade limiting assembly comprising a limiting member provided on the mounting rod and controlled to move a displacement stroke relative to the mounting rod, a limiting block provided in the first mounting hole, and an elastic member provided in the first mounting hole and connected to the limiting block, the limiting member comprising a limited position and an unblocked position in the displacement stroke, the limiting block located on a path of the displacement stroke, the limiting block comprising a stop position that the limiting block protruding a surface of the mounting rod to force the limiting member to locate at the limited position, and a release position that the limiting block sinking into the first mounting hole to allow the limiting member to switch between the limited position and the unblocked position, the blade limiting assembly comprising a first mode that the limiting block entering the stop position to prohibit the heel from detaching from the blade holder by the limiting member when the replaceable blade is mounted on the blade holder, and a second mode that the limiting block entering the release position to allow the limiting member to switch position so that the replaceable blade is detached relative to the blade holder.