This listing is for 1/8" diameter steel rod x 3 feet long. 30 pieces, an ample quantity to build a model trestle 3 feet long in any gage listed above. We recommend joining steel rod prices by solder, brazing or welding.  Glue or adhesives are not recommended. This type of model bridge construction is very strong when soldered, welded or spot welded. with 30 lengths of rod you can builded a model bridge 36 " long X 17" high in HO gage as shone in photos. other gages may change detentions slightly.  STEEL IS AISI 52100. 6 foot lengths are available in my store.