Steel beam question

[nuche1973]

I have a beam in an existing building. The following measurements were taken: bf=6 3/4", d=12 1/8", tf= 7/16". There is no exact date on the structure, if I were to guess it would be sometime in the 1950's. I have a copy of the AISC 5th edition, but cannot find a size that matches the dimensions. Is there a resource that I can use which lists unconventional steel shapes?
Any thoughts would be appreciated.

 

[dougantholz]

AISC Design Guide 15.
First determine if it is an S or B shape (tapered flange or uniform thickness). The shapes are grouped by depth, then flange width. Look there. I would take the smallest Section modulus in that particular group to make sure I get the most conservative design.
If you are a member of AISC, and it is VERY cheap for almost everyone in your firm to be a member, the design guides are available for free download.

 

[nuche1973]

Thanks, I appreciate the info.

 

[Umassengr]

If you are looking for a section that is no longer manufactured you could try to find it in an old fabricator hanbook. Bethlehem Steel pubished thier structural shapes in a book. and I found one on online this morning. Here is the Description:

"BETHLEHEM STRUCTURAL SHAPES. Information and Tables for Architects, Engineers and Designers. Bethlehem,Pennasylvania, Catalog S 58 A, No date but probibly published in 1958 judging from catalog number. Vinyl bound ring binder in Bright Clean VG+ condition. Some Content includes: Angles,Tees and Zees. Standard Mill Practices. Beams,Flanges, Bearings, Shipbuilding, Sheet Piling, Car Building, etc"

Hope this helps.

Instead of bidding on this one you could probably find one on a rare book site.

 

[ronster]

You have a WF12x27 or WF12x31. Field dimensions of old steel beams tend to be slightly higher than book dimensions due to to rust scale and painting. I would conservatevly assume a WF12x27. You can take wire brush to the beam and use a micrometer to try to get a more accurate measurement.

 

[nuche1973]

Thanks, I appreciate it.

 

[msquared48]

You could also get yourself a copy of "A.I.S.C. Iron and Steel Beams 1873 to 1952", and also, copies of the 1956 and 1963 editions of the AISC Steel Design Manual for the timeline to which you are alluding.

Mike McCann
MMC Engineering