Open end wrench capable of fast driving and having high toughness and a long service life

摘要: An open end wrench includes a body having jaw portion for holding workpiece. The an arcuate sliding groove, expanding and slider movable relative to the groove along path. first force-applying face evasive adjacent face. When deforms elastically while wrenching workpiece, increases effect within elastic limit of portion, such that corner between force-receiving in rotating direction sixth second can move across into avoiding damage resulting from failure withstanding reactive force Thus, has high toughness long service life.