Abstract: A one-way open-end wrench includes two jaws and a swing block. The first jaw includes a flat face, a concave face, and a supporting element extending on the concave face and including two flat ends. The swing block includes two fins extending on an upper face of a platform. Each fin includes a convex face corresponding to the concave face. The fins are connected to the supporting element so that the swing block can swing relative to the supporting element. The lower face of the platform does not extend parallel to the flat face of the first jaw when the first flat end of the supporting element contacts the upper face of the platform. The lower face of the platform extends parallel to the flat face of the first jaw when the second flat end of the supporting element contacts the upper face of the platform.

Abstract: A one-way open-end wrench includes two jaws and a swing block. The first jaw includes a flat face, a concave face, and a supporting element extending on the concave face and including two flat ends. The swing block includes two fins extending on an upper face of a platform. Each fin includes a convex face corresponding to the concave face. The fins are connected to the supporting element so that the swing block can swing relative to the supporting element. The lower face of the platform does not extend parallel to the flat face of the first jaw when the first flat end of the supporting element contacts the upper face of the platform. The lower face of the platform extends parallel to the flat face of the first jaw when the second flat end of the supporting element contacts the upper face of the platform.