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KG / mm square and loading

KG / mm square and loading

KG / mm square and loading

(OP)
Hi,
I have been informed by the bracket supplier of a safe load figure of 72.12 kg/mm sq for 8mm threaded rod.

I only know my pipe weights in kg / metre.

How do i calculate if the 72.12 kg/mm sq is of sufficient strength to hang the pipe. Is it simply 72.12 x the cross section of 8mm?

Thanks
Lee

RE: KG / mm square and loading

72.12 kg/mm is 72,120 kg/m or about 48,400 lb/ft... seems a tad high...

Dik

RE: KG / mm square and loading

That's kg/mm^2, which comes to about 103ksi, which is the allowable stress of the rod.

For this case you would multiply the 72.12kg/mm^2 by (8mm)^2 x pi / 4 = 3625kg.

That's what the threaded rod will hold.  Now take your pipe length and multiply by its weight in kg/m to get its total weight at that bracket.  If it's less than 3625kg, it's OK.



If you "heard" it on the internet, it's guilty until proven innocent. - DCS

RE: KG / mm square and loading

that'd be mm2, an 8mm rod is 64mm2, 72.12*64 = 4616kg = 10154lbs (maybe a little high for a 5/16" rod ... it'd be a threaded rod, so use the minimum area (which would be less thean this quick calc) ... thinking about it, what does "safe" mean to you ? sustainable load (= ultimate in my biz), about right; = working (= sustainable/SF), sounds high.

i think the load you have is the maximum sustainable load, so you could always test one to see.  

RE: KG / mm square and loading

ok, i'm a dumb-ass ... thx for pointing that out swearingen !

RE: KG / mm square and loading

Is the applied load from the pipe is purely shear I would assume 0.6 x the capacity of the rod (ref BS 5950). Generally the load from the pipe for each bracket should also be factored appropriately taking into account its dead weight and the Imposed or live load of the material in the pipe.

RE: KG / mm square and loading

engvin,

I think these are hangers loaded only in tension.

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