What is this Steel shape?

[bigmig]

I was inspecting a prefab metal building the other day and came across a mezzanine floor that was framed with 12" deep x 2" wide "C" shapes. These are not metal stud (cold formed), and they aren't in the AISC steel book. They are hot rolled (?) and are about 3/16" thick. I have attached a photo. what is the generic category of this type of steel shape and where would I look for design specification?

I have seen this "type" of steel most commonly used on metal building girts. I saw some the other day used in a precast hybrid concrete panel (3" thick panel with 6" studs at 24" on center).

I just have never used this stuff and would like to start.

 

[MikeHalloran]

No photo.

I think you are describing 'stair channels'.

Mike Halloran
Pembroke Pines, FL, USA

 

[dhengr]

Bigmig:
They could be a break formed section, depending upon their length , by the PEMB manuf’er., in their own shop. They could be a proprietary rolled shape done for the PEMB manuf’er., by a mill. A section that they use fairly often for several different things, and in sufficient quantity that they can afford the set-up costs for a mill run. There are many proprietary sections out there. They pay for the special set of rolls or combine several existing rolls in the mills inventory; then they have to pay for set-up and buy in sufficient quantity to induce the mill to do the special rolling for them. Maybe they get a special price from one supplier on 3/16" coil stock, and then can design around a constant thickness section. I suspect that in that thickness, that stock could be slit and then cold rolled in a secondary processing shop. I think you should try to get the info. you need directly from the PEMB manuf’er., because you will at least need the thickness, other dimensions, and a mat’l. spec. and properties.

 

[hokie66]

If they are hot rolled, the outside corners will be relatively sharp, but if cold formed, they will be rounded. Agree with BA that they sound most like a miscellaneous channel used for stair stringers, but a MC 12x10.6 is only 1.5" wide.

 

[RWW0002]

There is a new Misc. Channel in the AISC manual that is close to your shape. AISC-14th edition has a MC12x14.3 (d=12" bf=2.12, tf=0.313, tw=0.25). I can not speak to availability, but I would think it would be more available than a custom-rolled shape

 

[bigmig]

Here is the photo of the shape.

 

[hokie66]

Not sure, but it looks like it has lipped flanges, which would make it a cold formed CEE purlin shape. I doubt that it would be 3/16" thick, though.

 

[EngineeringEric]

3ga is almost 1/4", 7ga is .179",
therefore 7ga (alomst 3/16") CEE seems to be what you have. Probably not off the shelf item.