Allows structural attachment to metal beams, bar joist, channel, or angle iron in top mount position only unless used on a parallel flange. Lightweight, one-piece stamped body provides superior strength and eliminates deficiencies associated with castings. Spins onto threaded rod and allows for easy adjustment. Conforms with Federal Specification WW-H-171 (Type 23), Manufacturers Standardization Society ANSI®/MSS-SP-58 (Type 19).