Density of A500 Steel 1

[Rabbit12]

Discovered something interesting yesterday.

I was defining a material in Risa 3D and I noticed the density of A500 Gr. B steel was 527 lb/ft^3 as a default. Everything else was 490. I asked around the office and out of 6 people, Risa used 527 for the density for three people and 490 for three people. Is this a Risa glitch or is A500 actually more dense?

 

[wannabeSE]

They may be compensating for a reduced wall thickness. In AISC, A500 HSS is designed with 0.93 x nominal wall thickness. 527 x 0.93 = 490

 

[Nor Cal SE]

Good catch, wannabeSE, as I had not actually known about the 0.93 factor for A500 HSS.

 

[cal91]

wannabe is correct - if you look in your manual and divide your HSS shapes Wt/Foot by Area, and multiply by 144, you'll get between 517 pcf for thick shapes and 527 pcf for thin walled shapes. Do the same for open sections and you'll get around the expected 490 pcf.

 

[wannabeSE]

The AISC 360 requirement is in section B4.2

 

[Rabbit12]

Thanks for the responses.