Abstract: A plastic wrenching tool wherein the axes of the fixed and movable members are maintained substantially coincident, and rotation or displacement therebetween minimized by the provision of grooves and projections on the fixed and movable members respectively. At least the outer convex portion of the tool is made of resin. The resin material used is fibrous glass reinforced plastic which may be used for the entire tool. Specifically a fibrous glass reinforced nylon resin is used as the material of the tool. Alternatively, a matallic material may be used in a part or parts of the tool, such as in the outer concave surface portion, the inner portion of the tool, or the concave portion of the outer surface of the tool and the inner portion of the tool.

Abstract: A hand tool having two arms pivotable about an axis, including a frusto-conical hole which extends continuously through both of the arm members and has a large diameter end and a smaller diameter end. A frusto-conical tapered pin is inserted into the large diameter end of the hole and a fixing member for engaging the tapered pin is inserted into the smaller diameter end of the hole. Once the pin is engaged by the fixing member, the arm members are pivotable about the common axis of the hole, the tapered pin and the fixing member.

Abstract: A wrench comprises a lower jaw member which has a handle portion, and is provided with a lower grip teeth portion formed in its front end surface adjacent to which a longitudinal guide hole is formed therein; an upper jaw member which has a substantially reversed-L shape, and is provided with a leg portion inserted into the guide hole of the lower jaw member in a slidable manner, and has an upper grip teeth portion formed in a head portion thereof so as to be opposite to the lower grip teeth portion of the lower jaw member, and has a longitudinally elongated hole formed in the leg portion; a swingable pawl which is inserted into the elongated hole of the upper jaw member and supported by a supporting pin both ends of which are mounted on opposite walls of the guide hole of the lower jaw member, and engages with a side wall of the elongated hole of the upper jaw member in detachable manner; and a spring for urging the upper jaw member always to its gripping position.