Screw Size : #8 x 2-1/4 Screw Size : #8 x 2-1/4 Product Features Carbon steel, coarse single thread. Non-threaded shank allows 2 materials to be pulled tightly together. Application: Wooden decks in the outside area The fixing thread fixes the top board Minimises creaking of floor structure The small cylinder head pulls flush into the wood and provides the perfect appearance