Grade A572

[Arunkumar.G]

Is there A572 grade of profile angle and channel available . Is that approved or mentioned in aisc design.

 

[dauwerda]

Yes, per the AISC steel manual A572 is an alternate material for rolled shapes. It should be available, but probably not as readily available as A36 for those shapes.

 

[phamENG]

A572 Gr. 50 is actually the preferred material for angles now, and A992 for channels. Here's the latest "Are You Properly Specifying Materials" Article from MSC (June 2022).

"Preferred" doesn't mean your fabricator will have it. I'm honestly not sure how much of this is based on surveys of industry trends or AISC trying to force a new trend, but I think it's probably more of the former. Best to check with the fabricator, though, if you're not sure.

 

[dauwerda]

Thanks phamENG, I didn't know that! I know almost all plate is dual certified as A572 Grade 50 and A36, so it doesn't surprise me that A572 will/has become the preferred material for other rolled sections as well.

 

[phamENG]

No problem. I was just updating some notes and specs yesterday and I noticed one that was out of date, so I went hunting for the latest chart. I haven't been doing much steel lately (other than the occasional frame or beam for a house) so I still haven't paid for the new manual yet....

 

[dauwerda]

The 15th edition is what I referenced, so I guess we will have to wait for the 16th edition for it to show what your linked article has.

 

[Enginerdad]

I wonder why W's and channels are "preferred" in a different grade from the rest of the rolled shapes. It looks like A992 is really just A572 Gr. 50 with some special requirements.

 

[phamENG]

As I understand it: A992 was born out of the Northridge Earthquake. You had a bunch of plastic hinge formation assumptions based on A36 steel with a minimum yield of 36ksi yield but no maximum, and by then a lot of A36 was coming out of mills at 50-60ksi. So...plastic hinge assumptions weren't quite right. A lot of seismic performance issues ensued.

A992 sets a maximum yield stress so plastic hinges are easier to predict and seismic performance can be more easily 'dialed in'. All those other shapes are generally not used in SFRS beams and columns, so they don't need the added requirement.

I'm sure somebody can clean up my rough memory of the history of A992.

 

[Luceid]

Another ChatGPT spammer?

 

[phamENG]

Who are you referring to, Luceid?

 

[jerseyshore]

A spammer that I reported about 30 times last night.