Blade change mechanism for power tool

A blade replacement apparatus for replacing blades connected by a bolt, the bolt extending along a first axis, comprising:

• a nut that fits the bolt to fix the blade;
• a nut loosening/tightening member;
• and
• an operating member, one of the nut loosening/tightening member and the operating member is provided with a first matching portion, and the locking member is provided with a second matching portion;
• wherein the operating member is movable between an operating position and a non-operating position, the operating member allowing a user to perform an operation by hand without using any instruments;
• wherein when the operating member is in the non-operating position, the first matching portion engages with the second matching portion, the locking member and the operating member rotatable to one another, and the rotation of the nut loosening/tightening member around the first axis is obstructed by the locking member;
• and
• wherein when the operating member is in the operating position, the first matching portion is disengaged from the second matching portion, and the rotation of the nut loosening/tightening member around the first axis tightens or loosens the nut.