Versatile wrench fits all nuts and bolts to 1-1/2'' (38 mm). Eliminates the need for carrying several fixed-size wrenches. Forged from select alloy steel with continuous-taper handle for aligning bolt and/or rivet holes. Industrial black finish for corrosion resistance. Precision-machined jaws are individually chosen and assembled by hand for smooth operation. Heat-treated for long life. Rail is ground for precision fit. Knurl turns smoothly for easy operation..