Bar Marking

Understanding Reinforcing Steel Identification

Reinforcing bars (rebar) are manufactured with standardized markings that provide essential information about each bar’s origin, size, material type, and strength. These permanent markings ensure complete traceability from the producing mill through fabrication and installation, helping contractors, inspectors, and engineers verify that the correct reinforcing steel is used for every project.

Standard Rebar Markings

Each reinforcing bar is manufactured with a series of identifying marks that provide important product information:

• Mill Identification – The first letter or symbol identifies the producing steel mill.
• Bar Size – The second marking indicates the nominal size of the reinforcing bar.
• Steel Type – The third marking identifies the type of reinforcing steel:
  
  • S – Carbon Steel (ASTM A615)
  • W – Low-Alloy Steel (ASTM A706)
• Grade Designation – The final marking identifies the yield strength of the bar, including Grade 60, 75, 80, 100, or 120. Grades may also be indicated by longitudinal lines:
  
  • One line = Grade 60
  • Two lines = Grade 75
  • Three lines = Grade 80 or 100
  • Four lines = Grade 120