paperlined.org
prominence > vertical
document updated 12 years ago, on Sep 22, 2011
I'm looking for a quick and flexible way to clamp onto the bottom of I-beams, for the purpose of buildering.

I'm looking for something akin to the American death triangle anchor, since in this case, I actually desire the lateral forces, since that helps secure the anchor.

McMaster-Carr

Go their website, and look under the I-Beam clamps section: Look under plate lifting clamps:

Failure modes of the "grab hook" / American death triangle design

Lateral swinging could cause one of the hooks to yaw. The fatal downside of grab-hooks, compared to all other anchor methods, is that they aren't yaw-stabilized. If one of the hooks yaws enough, it can come completely off. Once one hook fails, the other one will almost certainly fail.

Desired behavior under lateral loads

The anchor should either: In all circumstances, it should RESIST ROTATING. Linear motion is acceptable; rotational motion is not.