structural general

[trivedi123]

I have come across structural member "6B20" from old drawing. Anybody knows section properties for this member ?

 

[EZBuilding]

This reads to me like nomenclature used in addition to a beam schedule. This would be the "20th" beam on the "6th" floor of a project.

 

[jayrod12]

No this is a light beam. It's like a wide flange beam but a little narrower and stockier. It will be something 6" deep and 20 lbs/ft.

 

[jayrod12]

Look in some older AISC books, maybe the 60s era. you should find what you need.

 

[structSU10]

Yea, if the general notes page on the set of drawings you have does not state the code it used, look at the date on the drawing. Based on the year you can go find the applicable AISC that will have the beam sizes. Historic AISC manuals are free downloads if you are an AISC member.

 

[phamENG]

What sort of drawing? How old? Where is it located? The older it is, the less standardized and more regionally dependent these things get.

I see most of your posts are road/highway related. Is this a highway bridge girder? What kind of material? My first instinct was Bethlehem Steel, but they only went down to B8s. The do have B9x20.

 

[JLNJ]

It's most likely W6x20 or 6WF20. 6" wide and 6" deep.

A lot of these old sections haven't changed because the rolls to create them on haven't changed.

 

[dauwerda]

Here is a link to AISC's historical shape database:

https://www.aisc.org/globalassets/aisc/manual/v15.0-shapes-database/aisc-shapes-database-v15.0h.xlsx

One thing to note, there is not a beam with this designation - it may be that it should have been called out as an "M" rather than a "B". You may need to get field measurements to verify this.
M is the designation for Miscellaneous, B is the designation for Light Beams, and JR is the designation for Junior Beams - These all have similar geometry to wide flange beams (WF).

 

[Ron247]

I think you will find it in the 5th edition. It is probably what they called a light beam or light column. Similar to a Wide Flange but designated with a B. 6B20 is probably what we would call a W6x20 now or an M6x20. You need to use the old edition info.

 

[SlideRuleEra]

Bethlehem produced B620 with slightly different properties at two different times, 1933-1934 and 1943-1948. The following is the excerpt from page 84, "AISC Iron & Steel Beams 1873 to 1952"

http://www.SlideRuleEra.net

 

[trivedi123]

Thank you jayrod12,structSU10 and phamENG,
My role is civil/structural.
This is two story building built in early 60s. During modification, I came across this section, that I can't find section properties and looking for help. I have looked into old USS book shapes and plates.[ couldn't find any information. I will check old AISC as suggested by jayrod12 and structSU10.
This is a structural beam in structural wind resisting frame.

 

[trivedi123]

Thank you all.
You all are big help. The website by dauwerda provides my answer.
Once again thank you all.