Non-Weld Bow Spring Series All Categories Our NWB Series use heat treated, spring-steel bows with reinforced collars. However, they differ from the Welded Bow Style (WBS) and use a locking tab in place of a weld to attach the bows to the hinged collars Model 112 Single RiseSingle rise bow spring View Product Model 116 Positive BarFormed “U” Shaped Bar View Product Model 117 Double RiseDouble-Rise bow spring View Product