DIYbanter - View Single Post - How much weight can a 3/4" black iron pipe support hanging from its threads?

(Stu)

Does anyone know where I can find the tensile strength of .75" iron
pipe hanging from its threads. IOW how much weight may I safely hang
on a .75" pipe screwed into a female thread in a flange secured to the
ceiling.

I don't know what the engineers will say, but I think you have too many
unstated variables to get a meaningful answer.
The pipe itself is mild steel (common name, "black iron').
What's the flange made of? Is it of the common cast iron sort?
What ceiling material is the apparatus being screwed into?
What material and dimension are the screws?
Is it for dead or live loads?
My suspicion is that you'd have failure of some component other than the screw
threads first.
The components you're using are not intended as a form of hanging-load
fastening system. Perhaps it would be better to consider some other form of
load carrier, such as some methold of tying into the joists (rather than merely
"ceiling") above.

On the other hand, I've seen some heavy cast iron stuff lag screwed into joists
in older machinery transmission, for ex, the hangers for lineshafting and
countershafting.
Frank Morrison.