Direct Answer
An anchor bolt plan is an overhead view showing the exact location, diameter, projection, and grade of every anchor bolt cast into the concrete foundation. It must be issued before concrete is poured — typically the very first deliverable from the detailer — because relocating or adding anchor bolts after concrete placement is extremely costly.
Full Explanation
Anchor bolt plans show bolt group layouts relative to column grid, edge distances, embedment depths, and sleeve or template requirements. They also specify bolt material (typically F1554 Grade 36, 55, or 105) and projection above the finished slab. The structural engineer must approve anchor bolt plans before they go to the concrete contractor. The detailer produces them from the column locations and base plate designs in the structural drawings.
What This Means for Your Shop
As a steel fabricator, you are responsible for coordinating anchor bolt plans with the GC early. If concrete is poured from incorrect or unapproved anchor bolt plans, you may need to field-drill, epoxy, or replace bolts — all at significant cost and delay.
Common Mistakes
Letting the GC pour concrete without a formally approved anchor bolt plan. Even minor deviations (1/4" off grid) can prevent base plate installation and trigger expensive remediation.
Recommended Process
As soon as you have design drawings, request anchor bolt plans as the detailer's first deliverable. Submit them to the engineer for approval on an accelerated schedule. Confirm the GC has received the approved plans before any footing or pier concrete is placed.