A-7 to A-36

[jike]

What year was the transition from A-7 (33 ksi) to A-36 (36 ksi)?

 

[boo1]

ASTM A7 was withdrawn and replaced with A36 in 1967.

A7 was typically either 30,000 psi or 33,000 psi min depending on when it was produced. I believe it was based on 50% of tensial

 

[BAretired]

Here is a link suggesting an earlier date:

http://www.eng-tips.com/viewthread.cfm?qid=143671&page=413

BA

 

[paddingtongreen]

AISC allows that the steel be checked per A36. I remember something to the effect that, "The steel doesn't know under which code it was designed."

Michael.
Timing has a lot to do with the outcome of a rain dance.

 

[frv]

@paddingtong..

?? I'm not sure I follow.

Yes- the steel doesn't know what code it was designed under, but it most certainly DOES know it's yield strength. If the A7 steel has Fy=30 ksi, and you check the building assuming Fy=36, you've just added 20% capacity on a whim.

 

[frv]

Dang!! one of my all time pet peeves, and I did it.. "its"

 

[mmillerpe]

I believe what paddington was referring to was using the updated spec with the old material strengths, therefore using the 9th thru 13th manual spec equations in lieu of 1/2 tensile strength for allowables depending on what juristiction you are in.

 

[paddingtongreen]

mmillerpe is correct.

AISC Q&A here:

http://www.modernsteel.com/steelinterchange_details.php?id=89

Michael.
Timing has a lot to do with the outcome of a rain dance.

 

[boo1]

ASTM shows A7 withdrawn and replaced by A36 dated 1967

http://www.astm.org/DATABASE.CART/WITHDRAWN/A7.htm

AISC Design Guide No. 15, table 3.2 lists Allowable Stresses in Early Steel.

The early 1900s steel was, ASTM A7 for bridges and A9 for buildings. Both consolidated in A7 steel in 1939. In the early 1960 A36 was available.