The ones with threaded holes are rod hangers. The chamfered holes are for flat headed wood screws that hold the hanger to wood, then a machine threaded rod is inserted into the tapped hole.
Commonly found on the ceiling portion of wood buildings to hold hanger rods for sprinklers and other heavy suspended items. They were made by a sadistic sumbeach who gloated on the screwdriver twisting he caused workmen to do.
The Hines brackets appear to be guides for transom window operating rods such as the units found in a swtooth roof.
You don't use regular screws, you used to use drive screws and hammer them in. Drive screws have been outlawed for a couple of decades now for fire sprinklers, but by then we had cordless drills to drop off of the lift. MEP trade labor always cost too much to waste time being sadistic to. My cost today for a journeyman fitter is right at $69 per hour - they only see $34 or so on their check, the rest is insurances, taxes, pension fund, supplemental pension fund, education fund, etc. (Point is, we do anything possible to save field labor) It was hard enough installing 6" and 8" schedule 40 pipe.
Typically they are hammered in with a 10" pipe wrench. (J/K)
Chilly
