Structural steel strengths

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OK guys where can I get some info on tubing strenghts etcc...I recently built a stand out of 6 x 6 x 3/8" tubing for legs which were 36" tall and 4 x 4 x 1/4" tubing for the cross pcs on top and 12" up from bottom, boxing in the stand. This was to hold up 12,000 lbs. of liquid in a metal container,so my customer says.Now he wants a stand built for a container that will weigh around 8,000 lbs. when full. I think 4 x 4 x 1/4" tubing will be enough for legs and top cross pcs. and maybe use 3 x 3 x 1/8" to tie the bottom of legs together.Any how where can I get some booklet or guide to go by for I know this customer hasn't a clue and I am no engineer. Looking for a guide of some sorts.Last edited by Jerry; 02-18-2004 at 07:40 PM.J P Streets Welding LLC
Reply:There are some engineers hang out here,, but,, I can tell without looking it is going to be strong enough.  A 6 ton jackstand dont weigh but 15 lbs tops.  They go to 23 inches and they designed so you can be working on the vehicle.  That thing is going to be absolutely 10 times as strong.  I bet it would take dam near a 100 tons to crush a piece of the 4x4 on end like it would be on your leg.  I think I might be tempted to keep the bottom leg ties heavy considering minimal cost depending on where it was going, and the span from leg to leg,, just in case some peckerweed nails it down low with a forklift full bore,, maybe its just overkill though too.  I built some heavy duty guard rail to protect a machine,,, then they were going to "save some money" and they had the maint man bolt it to the floor with some 3/8 lags and shields,, duh,, I wonder why I had 3/4 holes in it???????  Ya, sposed to have 3/4 x 6 Hilti style anchors to protect people standing next to it from being rammed from forktruck... Haha,, you think those lead shields and 3 inch bolts gonna do it?Last edited by Sberry; 02-18-2004 at 07:59 PM.
Reply:A limited ammopunt of info is in the machinery handbook, but what you really want is the american institute of steel construction handbook (AISC)Collumns typically fail by buckling, the figure of merit is called the slenderness ratio.  Suffice it to say 36" tall 4x4 ain't slender and will take a hell of a load.  it will need to be anchored to the floor, gusseted, or the leg tied together to keep the welds from being over stressed under "dynamic loading" (the fork lift)