Wood to Wood or Wood to Steel Screws (Interior). WSC Series - #8 wood screw, 2/3 rolled, coarse thread, sharp point, flat head, yellow zinc coating. WSCLT134S - #8 wood screw, fully threaded, sharp point, yellow zinc coating. WSNTL Series - #8 wood screw, twin threads, nibs, sharp point, flat head, yellow zinc coating. PPSD Series - #8 wood to steel screw, #2 drill point, flat head, yellow zinc coating.