Non-typical steel angles in OWSJ

[wsg SE PE]

Hello all,

I stumbled across a few non-typical steel angles in some open web steel joists and joist girders (supplied by Vulcraft) yesterday. The web members in particular induced some head scratching.

Some of the shapes I measured with my calipers were coming in around .110" in leg thickness. This includes a coat of primer on each side of the leg, which I estimate (rough WAG based on some web searching) to be around 4-6 mils each, giving me a net steel thickness of around .10. As we're all probably aware, none of the standard angle shapes, as tabulated in the AISC manual are thinner than 1/8". Additionally, many of these angles have leg lengths smaller than 2", which is the smallest leg length listed in the AISC manual as well. I am struggling to determine exactly what size/thickness these angles are.

So, I guess I'm curious if anyone has a good reference for non-standard structural steel angles? Or better yet, does anyone have experience with steel joist design and fabrication as practiced by the typical US suppliers and know what types of cross sections they tend to use for smaller members. (I am familiar with the SJI Standard Spec.) I knew/assumed that the manufacturers used nonstandard shapes, but I'm curious if there's any sort of general size "standard" that these non-typical shapes are manufactured to. My Google skills are failing me.

Many thanks in advance for any helpful info or insight anyone might have.

Cheers.
Will

https://www.linkedin.com/in/williamsgodfrey

 

[XR250]

Could you tell if they were hot rolled or cold rolled? (hot rolled would have a sharp outside corner I'm guessing)

 

[JAE]

Go to this thread - some of the attachments that we provided here have some very old chord angle sizes. May not be applicable for current shapes used today, though.

thread507-261921



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[dhengr]

WilliamSGodfrey:
Some of those angles could be bar sized shapes, not regular structural shapes as shown in the AISC manual. Also, remember Vulcraft is part of Nucor, aren’t they? They roll their own steel, to their own specs., for OWSJ, as long as the jsts. pass muster. In any case to save a pound of steel per foot, and assuming they use large enough quantities of a given size and material, they can get most any size angle rolled in a mill run quantity, or by agreement with the mill. They probably own their own rolls at a given mill, for that shape. There are a number of industries which have special shapes rolled for their use.

 

[Triangled]

yes to all the above
and, can you get a joist tag? With this you can contact Vulcraft for further info on specific job.

also, you'll want to know what steel grade they used. More recent joists typically utilize 50 ksi steel. Prior to that it was 36 ksi steel, and prior to that... and so on.

.110 does not sound unreasonable

 

[wsg SE PE]

XR250, I am pretty confident they were hot rolled. Sharp corners.

JAE, many thanks for the reference. I will review.

dhengr, thanks for your thoughts. I arrived, more or less, at the same conclusion. Vulcraft is owned by Nucor and most definitely probably roll their own shapes. Was curious if there's a spec publically available about the shapes they might use most commonly. I can physically measure the members well enough for our analysis, just looking for context.

Triangled, we do have tags. Vulcraft claims to not be able to provide info currently. The joists are ~15 years old. We also anticipated the need for material testing and sent some specimens to a lab today.

I appreciate everyone's thoughts.

Will

https://www.linkedin.com/in/williamsgodfrey

 

[Triangled]

at 15 years old I'd be surprised if the steel was not 50 ksi....would really like to hear if otherwise

sounds like you've got this job nailed