The 1/2" x 4" Bolt is used with Internally Threaded Bollards (stainless steel, galvanized, or powder coated). They're sold individually. 4" x 24" and 4" x 32" bollards use (2) bolts each. 5.5" x 42" bollards use (3) bolts each. Holes should be made using a 1/2" drill bit.
Traffic Safety Products is a division of Eberl Iron Works, Inc.