... 2.decription:WS,ST,OR,DLD,SV 3.Brand:Longer guide bar nose:WS bar nose,ST bar nose,OR bar ... products are imported from America, which shares the same origin of materials with OREGON. And the type of the materials is SAE8660. Heat treatment is ... for stability and breaking, test for the hardness of its components, test for breaking of finished products, the quality of saw chain surface, test for ...