Drop In Anchors Failure Mechanism 1

[Bagman2524]

Drop in anchors have a larger allowable than expansion anchors for the same embed depth. Why is this? I assume drop-ins fail by a different mechanism than the 45 deg cone concrete pullout for expansion anchors.

 

[anchorengineer]

Not sure exactly which anchors you're using but it could be because a 1/2" diameter drop in is not 1/2" in diameter. It means that a 1/2" threaded bolt can be screwed into it. The Hilti 1/2" drop in anchor has a 5/8" outside diameter. A 1/2" kwik bolt 3 is 1/2" outside diamater. If concrete strength governs then theoretically you will get a higher load with a drop in at the same embedment. You would have to compare different manufacturers to be 100%.
Good Luck.