Anchor Bolts
CSI Division 05, Metals
Threaded steel bolts embedded into a concrete footing before the pour, left protruding so that a structural steel column can be bolted directly to the foundation once the concrete cures and steel erection begins.
Why it matters
Anchor bolts are the actual connection between a building's steel frame and its foundation, and their exact placement has to match the steel fabricator's drawings precisely, since a steel column's base plate is drilled for bolts in very specific locations that can't easily shift once the concrete has cured.
On a real project
Before a footing is poured, a crew sets a template holding the anchor bolts in the exact pattern the steel column's base plate will require, and double-checks the layout against the steel drawings before the concrete locks the bolts permanently in place.
Who this matters most to
A Ironworker bolts a column's base plate down onto the anchor bolts as the very first step of steel erection, and relies entirely on those bolts having been set correctly weeks earlier during the foundation pour.
Where this goes wrong
A foundation crew sets anchor bolts slightly out of position relative to the steel drawings, an error that isn't caught until a steel crew shows up weeks later to set the first column and finds the base plate's bolt holes don't line up, stalling erection until the problem is corrected.