Direct Answer
In modern AISC/ACI terminology, 'anchor rod' is the preferred term for the threaded steel rod cast into concrete to support column base plates. The older term 'anchor bolt' is still widely used in the field and means the same thing. Both refer to F1554 Grade 36, 55, or 105 rods (ASTM F1554 is the governing specification) or occasionally A307, A193, or high-strength grades for heavy industrial applications.
Full Explanation
ASTM F1554 provides three anchor rod grades: (1) Grade 36 — 36 ksi yield, most common for standard column base plates, can be hot-dip galvanized without risk. (2) Grade 55 — 55 ksi yield, weldable (supplemental weldability requirement available), often used where moderate tension demand exists. (3) Grade 105 — 105 ksi yield, for heavy tension applications; galvanizing restricted due to hydrogen embrittlement risk. Anchor rod geometry (diameter, embedment length, hook or plate washer) is designed by the structural engineer per ACI 318 Chapter 17. The anchor bolt plan drawing shows the X-Y location, elevation, and projection of each rod.
What This Means for Your Shop
Verifying that the correct F1554 grade is furnished is part of material receiving inspection. Grade 36 and Grade 55 rods look identical — the only distinction is the mill certification. Confirm grade from MTRs, not appearance.
Common Mistakes
Accepting substitution of Grade 36 rods when Grade 55 is specified without engineering review. The higher yield strength of Grade 55 is a structural design requirement — Grade 36 substitution reduces connection capacity and requires engineering approval.
Recommended Process
When receiving anchor rods, match the heat number on each bundle to the MTR and verify: ASTM F1554 designation, grade (36, 55, or 105), and any special requirements (weldability, galvanizing). File MTRs with the project close-out records.