Old steel designations

[jim57]

Looking at a building constructed in Yonkers NY. Have plans dated 1930. Having a hard time determining what the steel is. Have the AISC Steel book of old sections. Any reference book or help with the following:
9C25; 9C20 1/2; 18W42.7;6I;9W9 sometimes the w looks like a "u" or an upside down "u"; 8w;

As always thanks for the help

 

[12345abc6ttyui67]

Is that the screenshot you meant to post?

 

[EngineerTex]

Generally speaking, the size of AISC beams are notated by a nominal dimension of depth, a shape designation and finally, a weight per foot in pounds.

Without looking in any book anywhere, I would conjecture that these designations mean:

9C25; 9”nom. depth C-channel at 25#/ft
9C20 1/2; 9”nom. depth C-channel at 20.5#/ft
18W42.7; 18”nom. depth W-flange I-beam at 42.7#/ft
6I; 6” I beam with non-parallel flange profile
9W9 9”nom. depth W-flange I-beam at 9#/ft

Or did you already know this and you’re looking for something else?

Engineering is not the science behind building. It is the science behind not building.

 

[djhurayt]

ET is correct about the nomenclature, but I think the OP is saying these sizes are not listed in his book(s)

As in the 9" "C" section, the only 9 inch section currently listed are 20#, 15#, & 13.4#, no 20.5# "C" shaped listed
18W__ currently is either a 40 or a 46, no such thing as a 42.7 any more

https://www.engineersedge.com/materials/aisc_structural_shapes/aisc_structural_shapes_viewer.htm

My suspicion is that as steel production has gotten better the weight per foot has decrease for the same strength beam. The above link has structural properties for the currently available sizes. Once you can find an old enough copy of the standard you may be able to compare the structural data and find that a lighter section is as or stronger than what was used in the 30's

david

 

[jim57]

No Wrong screen shot. See new attachment

 

[12345abc6ttyui67]

Well, per the General Notes if an I and C does not have any weight listed on the GA it is to be per "AMER STD WTS AS -7-7 15.3 10(-10(15.3" as best I can make out. I am not familiar with this. Perhaps an old Steel Shapes standard?

As noted by others 6I etc. will be a 6" deep I beam profile, with weights per standard noted above.

As noted by others 9C29 etc. will be a 9" deep C channel profile, with weight 29lb/ft.

I believe the "n" shape is to signify a C section placed toes down and "u" will be a C section toes up.

 

[jim57]

Thank you. I think you are right regarding toes up and down. Could the "C" mean a steel mill eg Carnegie? At the site did not see many channels.

 

[weldstan]

Take a look at an old version of ASTM A-6.You should be able to get one from the New York City Library. Ask for something pre 1950, preferably pre 1940. You may also check the 1948 ASM Handbook.

 

[dauwerda]

AISC has documents for historical shapes available as well. You can find them here:

https://www.aisc.org/publications/historic-shape-references/#28348