... treatmentBlack Oxide,Zinc plated,hot dip galvanized,Dacrotizing plated and your requirementOthersWe can make accroding to your drawing or ... your sampleRegarding to Nuts Type of NutSquare,Hex,Flange,Hex socket,T-type, ... Coupling,wheel ,acorn,tapper,and so onRegarding to Washers Type of WasherRound ,Square,Plat,Friction,Plate ASTM A325 NUTS AND BOLTS HARDWARE