Steel Pricing 1

[phamENG]

I'm designing a couple of small buildings that require only a small quantity of structural steel framing (the remainder will be light-gauge framing). The budget is tight so I'm trying to do my part in keeping as many costs down as possible. The columns will be hidden within the walls, so I'm looking at a max size of 4 inches. A 3.5" nominal standard pipe checks out, but when I went to check RSMeans, they don't quote STD for structural columns, only X-Strong. I was also surprised to find that the XS pipe is more expensive than the HSS4x4x1/4 - the few purchasers/fabricators I've had the opportunity to speak to (I'm still a very junior engineer) have told me that pipes are MUCH cheaper than HSS of any shape.

My questions, then, are these:

1- Does the price per pound of steel vary significantly (or at all) with the various ASTM Standards and Grades (how does A36 compare to A500 to A996, and how does A500 Gr. B compare to Gr. C for price, etc?).

2- Is there a significant difference in the way pipes and round HSS are produced that could result in a premium? Is the manufacture of square/rectangular HSS that much more expensive than either of those?

Of course local availability plays a roll in the price, so let's consider that we're talking about comparable #/ft and stock quantities.

Thanks for any help or advice anyone can give me. I'm trying to make sure my designs are not only safe, but practical in as many aspects as possible, too.

 

[MikeHalloran]

A while back, I was buying significant quantities of steel.
The price ranged from $.30 to $3.00 per pound, depending mostly on whether what you wanted was in stock, and how far away it was.

Re pipe vs HSS; the requirements and certs are different; the manufacturing processes may or may not be similar. I.e., you can roll or brake form HSS, and it may be corner welded or face welded.
For HSS4x4x1/4, you should also look at W4x13.

Distributors choose what to stock for reasons of their own, and none of them carry everything that may be in their 'stock list'.

Especially if you only need modest quantities of steel, make up a quote request form in Excel and email it to your local distributors. State on the form that you intend to buy one or more of the line items listed, but not all. Use the exact quantities that you will need, and the exact lengths. Odds and ends accumulate, and sometimes that's exactly what you need, and a good price will be offered just to get it out of the way.


Mike Halloran
Pembroke Pines, FL, USA

 

[XR250]

If it is only a small amount of steel, the cost of the material isn't likely to be a big factor as fab. and erection labor are the more significant costs. You will probably spend more time in billable hours than they will save - a good exercise, nonetheless. Pipe is generally cheaper than HSS in my experience.

 

[phamENG]

Thanks for the quick replies. I'm planning to get in touch with local fabricators/distributors for their input as well, and hopefully check out some of their facilities - just don't have time before I need to turn this project around. I'll stick with the pipe for now and see how the contractor responds to it when it's time to buy it.

 

[AggieYank]

HSS tubes are a slight premium to round pipes for equivalent weight, as long as the pipes are "normal" sizes. "Normal" round pipe sections are cheaper than non-standard. I would consider the even-number-sized pipes to be "normal", and the odd-size pipes to be unusual. So, a 4", 6", 8" pipe will be cheaper than 3", 5", 7".

So, I could understand your scenario where the HSS tube is actually cheaper than the "non-normal" pipe section.

Also, never forget that its a free market, so prices aren't always easy and predictable (as MikeHalloran said well).

 

[racookpe1978]

Check very carefully for "pipe" shapes - intended for internal pressurized fluids, and "round structural tubing" HSSR. They are built to two different standards - and, very often, the guy quoting you will "assume" what he thinks you want - not what you really mean.

HSSR is straighter, more uniform, more costly because it is intended (in the specification and the material quality) to be able to resist compression structural forces against real building loads (impact, winds, earthquakes, and the like) for "people safety" . A deviation of imperfection in a "pipe" will actually straighten out under internal pressures of the fluid, and those fluid pressures tend to be uniform down the whole pipe - not concentrated like at outside beams and connection points to other strucutral loads which will add moment loads.

WF are slightly harder to connect to than HSS (square tubing) because they often need copes and angle iron pieces; and I prefer square tubing for its simple end connections - by WF have more surface area to paint and are slightly more difficult to paint because of the interior angles on all of the webs.

Square tubing can be mitered if needed.

Be careful as well with welded joints. I did save money recently getting thin-walled tubing for a gate at my daughter-in-law's garden. BUT! The thin wall tubing was much more difficult to weld to without burning through the very thin walls. It ends up it would have been much sipler just going for 11 gage tubing to make the fabrication 9welding) faster and simpler.

 

[JStephen]

Watch stock lengths- I recall in times past, we could get, say, 30' W-sections (actually cut from 60') but only 40' channels.
Typical pipe might be A53-B, which is a 35,000 psi yield, which is less than the A500B or C.

 

[dhengr]

StructuralEIT:
You would do well to do a little prelim. design to get a fairly good idea of the general sizes and quantities that you need. Then talk to a couple of your local fabricators who might actually do the job for you, and ask them what they actually have in stock in those sizes. Then do your final design around the sizes they have available. This will get you your best steel price. If they don’t have it in stock, they will have to go to a steel warehousing company for any small quantities.