There are a number of ways to identify reinforcing bar (rebar) from the production mill to the fabrication shop to the jobsite. This documentation and marking system helps provide a wealth of useful information about the manufacturing and composition of each bar of reinforcing steel.

Each Individual Reinforcing Bar is Manufactured with a Series of Individual Markings:
  • The first letter or symbol identifies the producing mill.
  • The next marking is the bar size.*
  • The third marking symbol designates the type of reinforcing steel — usually either "S" for carbon-steel (ASTM A615) or "W" for low-alloy steel (ASTM A706).
  • Finally, there will be a grade marking (60, 75, 80, 100, 120) or by the addition of one line (60) or two lines (75), three lines (80, 100), or four lines (120) that must be at least five deformations long.

*CRSI Board of Directors, through the Engineering Practice Committee, is encouraging producer Members to revert to an inch-pound bar marking system for all sizes and grades of deformed reinforcing steel products. The intention of this resolution is to reduce confusion and the chance of errors/delays from the construction supply chain.

American Society for Testing and Materials (ASTM) Bar Marking Sequence

Bar Marking Sequence