If my already installed anchor bolts got bent by accident, is it OK to bend them back?
The anchor rods in this photo were damaged because they were covered with snow and the equipment operator did not see them.
Every situation is different, and we try to not make recommendations where bent anchors are concerned as we feel it is a question better answered by the project engineer, as he/she will be more familiar with the specific situation. That said, the AISC has this to say about repairing damaged anchor bolts:
“ASTM F1554 permits both cold and hot bending of anchor rods to form hooks; however, bending in the threaded area can be a problem. It is recommended that only Grade 36 rods be bent in the field and the bend limited to 45° or less. Rods up to about 1” in diameter can be cold bent. Rods over 1” can be heated to 1,200° F to make bending easier. It is recommended that bending be done using a rod bending device called a hickey. After bending, the rods should be visually inspected for cracks. If there is concern about the tensile strength of the anchor rod, the rod can be load tested.”
– 2nd Edition of the AISC Design Guide 1, under Base Plate and Anchor Rod Design
So field bending F1554G36 is acceptable as long as it is not more than 45°, and is it done per the parameters in the above paragraph. For other grades of anchor, or if the bend is more than 45°, the project engineer should be consulted in order to make the proper decision.