Structural Angles 2

[Metaljon]

I am working on a project looking at transmission towers that were constructed around 1935 to 1950 period. The transmission towers are constructed with various sizes of structural angle up to 6x6 inches profile. The angles were constructed from steel grade CESA S40 which is medium tensile steel with properties Fy=33ksi and Fu=55 -65ksi. The angles were manufactured by the illinois steel company but the design drawings do not indicate as to what manufacture standard was used. Does anyone know what ASTM or CESA standard for structural angles in the US or Canada that would apply in the period 1935 to 1950's? I have tried going through the ASTM website but can't access any old standards.

 

[ajh1]

You are probably looking at ASTM A7 steel.

 

[metengr]

I would agree that ASTM A 7 would be a possibility. I do have a copy of the standard and it would apply.

 

[Metaljon]

Thanks. I would have never worked that one out going on the name of the standard.

 

[Metaljon]

I have reviewed the ASTM A7 standard. I am also interested in the dimensional tolerances of the angle sections similar to what is covered in ASTM A6 -12. What was used before ASTM A6? I have checked the ASTM website but it only gives historical version to 2000.

 

[ajh1]

A6 was first issued in 1949. AISC Design Guide 15 indicates it was first issued as a tentative standard covering delivery requirements for A7 steel. There is no indication in the guide of a previous attempt at an A6 style document. It is possible that A7 had additional content that was split off to form A6.

 

[TXStructural]

Many mills produce special sizes for specifically for use in towers and joists. I don't know about practices that long ago, but I suspect it was the same, so the sizes may be non-standard.