question for any engineers i think.

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Got a structural steel question that doesnt seem to fit into anywhere so im asking it here.what will hold up more?4"diameter 1/4" wall by 10' long pipeor4"x4"x 1/4" x 10' square section both steelid say the square box as there is more steel in it..... but never did the maths, and am paid from the neck down anyway.G
Reply:what direction are you loading it in ?
Reply:oh!they are vertical with the load vertically down on themin a basement holding up a wooden beam.I get these all the time with 4"x4" square tube.this one was 4"diameter pipe.engineers spec them so i was just trying to find the advantage over the other.or does it depend on what the engineers had for breakfast?lolG
Reply:The square column, because it has the larger moment of inertia.    Also has the largest cross sectional area.   Depending on how you look at it, one or the other is more important, but since both are larger for the square column, no question that the square column is stronger.This column is slender enough that buckling is a consideration, although it may not be the limiting factor.   The calculations to compute the safe load get a little complicated in that a lot depends on whether or not the ends of the column are considered to be fixed or pinned.   The conservative assumption is that the ends are pinned.  RichardSculptures in copper and other metalshttp://www.fergusonsculpture.comSyncrowave 200 Millermatic 211Readywelder spoolgunHypertherm 600 plasma cutterThermal Arc GMS300 Victor OA torchHomemade Blacksmith propane forge
Reply:Originally Posted by gordfraserGot a structural steel question that doesnt seem to fit into anywhere so im asking it here.what will hold up more?4"diameter 1/4" wall by 10' long pipeor4"x4"x 1/4" x 10' square section both steelid say the square box as there is more steel in it..... but never did the maths, and am paid from the neck down anyway.
Reply:Ok, you are going to have to be a little more specific.4" diameter.  Do you really mean 4" diameter or 4" pipe?  I will assume that you mean 4" Sch 40 pipe which is 4 1/2" diameter and 0.237" wall.If that is the case, the two are pretty close.  The square tube has a moment of inertia of 7.80 while the pipe is 6.82.  However, this number does not take into account the 12.5% tolerance on pipe wall thickness.  If it is actually 4" structural tubing 1/4" wall, the moment of inertia is 4.91.  (AISC Steel Construction Manual, 13th Edition).  That is a pretty serious difference.My personal preference is for square tube, but it is often more expensive than a heavier pipe section. Originally Posted by gordfraserGot a structural steel question that doesnt seem to fit into anywhere so im asking it here.what will hold up more?4"diameter 1/4" wall by 10' long pipeor4"x4"x 1/4" x 10' square section both steelid say the square box as there is more steel in it..... but never did the maths, and am paid from the neck down anyway.
Reply:Either one is more than adequate to hold up a basement beam in a house.To make either one stronger yet, fill it full of concrete."The reason we are here is that we are not all there"SA 200Idealarc TM 300 300MM 200MM 25130a SpoolgunPrecision Tig 375Invertec V350 ProSC-32 CS 12 Wire FeederOxweld/Purox O/AArcAirHypertherm Powermax 85LN25