Square bar designation 1

[Prestressed Guy]

W12x22x12'-0" for wide-flange.
L4"x3"x3/8"x2'-0" for angle.
C8x11.5x10'-0" for channel,
FB3/8"x2"x1'-0" for flat bar.

How do you call out hot-rolled A36 square bars?

 

[RobertHale]

AISC's recommendation is to use the plate designation, PL3/8x4 1/2x2'-0", for all plates, sheets, and bar materials. Therefore your square bar designation would be something like PL1 1/2x1 1/2x10'-0". This also means your flat bar designation is a little anachronistic. Also, note the designations for angles should not include the inch marks for everything but length e.g. L4x3x3/8x2'-0"

Robert Hale, PE

 

[msquared48]

And if the bar is twisted?

Mike McCann, PE, SE (WA)

 

[wannabeSE]

Robert
Last I saw, AISC said that flat bars where commonly specified as plates. When did they begin recommending the plate designation rather than noting that it is a commonly used alternative to FB?

 

[RobertHale]

wannabeSE, this recommendation was present in the 3rd ED LRFD manual (pp 1-9), where the phrasing makes it sound like a new thing. Then it is also present in 13th and 14th and 15th ED manuals (pp 1-8 & 1-8). There is a little difference in the example call out in the 14th ED but I think that might have been a typographical error.

Robert Hale, PE

 

[racookpe1978]

Yes, I know it "sounds official" from an "official" AISC publication, but it is still foolish.

Yes, "plate" could be designated that way, but it is more intuitive to use FB (flat bar) for some items (width x thickness for so-and-so length) when items are purchased by length; and when the purchased item is cut to a designated length. It is far more natural to use "plate" when those are purchased by area, then cut to size for fabrication. A 2x 1/2 flat bar is NOT cut to area, neither is a 1/2 x 1/2 sq. I suspect the change was pushed by people selling software/design/CAD packages to simplify THEIR material ordering routines.

 

[wannabeSE]

Thanks Robert. Need to coordinate specifications and general notes. We specify A572 Gr 50 plate because it is common. I need to coordinate with bars. I am guessing Gr 50 flat bars are common. Need to check on round and hex.

 

[JAE]

Look at your AISC Manual - in my 15th Edition, Part 1 (page 1-9) it states:

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[JStephen]

I'd just call it out a __"x__" square bar x __" long and be done with it.
If you have to research how to designate it, there's a good chance someone else will have to look up what your designation means.

 

[JAE]

There's also this old thing I had - It is from AISC and shows the "old" way to call out shapes and their "new" way.
This shows a curious way to call out "Bars" vs. Plates.

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[Prestressed Guy]

Wow! Thanks, I think. Who would have thought that this question would go to 10 responses!? I kind of like the BAR 1■ but PL 1x1x1'-5" sounds like it is more in keeping with the current references.