Vanadium steel scaffold spanner with zinc plating for rust protection. Hexagonal 7/16" Whitworth head. Swivels 180º for ease of use. Tayler Tools Whitworth Scaffold Spanner 7/16" in Silver Chrome Vanadium Steel. Tayler Tools 11mm / ⁷⁄₁₆" Scaffold spanners are wrenches specifically designed for tightening and loosening nuts and bolts on scaffolding. They typically have a long handle for increased leverage and a wide jaw opening to accommodate the larger nuts and bolts used in scaffolding construction.