Old style beam - what size?

[richburton]

http://www.fileden.com/files/2007/3/25/925948//Beam.pdf

The drawing shows an old style beam that doesn't appear in my steel book. The beam supports the wood floor of a building built in 1920. What size is this beam? Is it an "M" shape or an "S" shape?

Section modulus and moment of inertia would be helpful too.

Thanks!

 

[richburton]

I could assume that it has similar properties compared to an S7x15.3.

Moment of inertia: 36 in^4
Section modulus: 10 in^3

 

[msquared48]

The mixed shapes of the flanges, top to bottom, looks like it might have been used as a crane rail. Looks like a hybrid of a wide flange and an "S" shape that you mention.

I found a 7" American Standard beam with a 3.75" flange on page 28 of the AISC Iron and Steel Beam (1873 to 1952)manual, however, both top and bottom flanges are tapered, with "n", the flange thickness being .25".

I = 39.58 S = 11.3, r = 2.77, all major axis values. 17.5#/ft

Nowhere in that catalog does it show any mixed flange shape arrangement. Could be proprietary.

Two other beams of the same overall size are also listed at the bottom of the same page. Both are 14.6 #/ft with I's around 35 and S around 10 as Rich previously mentioned.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask