Positive engagement spanner wrench

The present invention relates to the field of hand tools such as are used for holding and turning collars, and more particularly, to spanner wrenches and vice-grip pliers. Apparatus for engaging and turning spanner type threaded members has an upper jaw member extending from a handle and terminating in a 90° arcuate radiused portion. A cylindrical lug extends radially at the end of the radiused portion for engaging the threaded member, and a clamping jaw member is pivotally connected to the handle so as to be diametrically opposed to the lug. The clamping jaw member is forced toward the upper jaw member to provide a clamping force on the threaded member and force the cylindrical lug into positive engagement with the threaded member.