Threaded Rod - F1554, A193 B7, & AISC Table J3.2

[BSVBD]

Since 2007, F1554 Grade 36 has replaced A307 for A36 threaded rod.

For higher tensile values, for threaded rod, I am told by a local supplier that both A491 and A325 do not exist.

Is A491 the same as A490?

This same supplier offers A193 B7.

Where can I find dependable strength values for all ASTM "A" or "F" or "OTHER" materials from a reputable author such as AISC or ASTM? I'd rather not depend solely on data provided from suppliers.

AISC Table J3.2 is not helpful regarding the apparent available materials (at least for my area - does material availability vary greatly nationwide throughout the U.S.?) for threaded rod. I'm ok with doing the math of the 0.75Fu. It just requires more leg-work than taking advantage of the various AISC tables available for other applications.

On a related note, where AISC Table J3.2 refers to Appendix 3, when following the formula at Appendix 3.4, my net tensile area for a 3/4" diameter threaded rod equals only 0.33 sq in. I'm ok with the outcome, if this is the correct procedure. I just don't want to apply too much unnecessary safety with non-applicable formulas.

Also in AISC Table J3.2, note [d], what is meant by "upset rod"?

In conclusion, for threaded rod tensile strengths greater than F1554 Grade 36, is there a more preferable solution than doing the research and math for A193 B7?

I feel like I'm throwing out a lot of information and too many questions for a single thread.

Thank you all for you assistance!

 

[ajh1]

The AISC formulas use the full cross-sectional area of the rod rather than the net tensile area. The 0.75 on the 0.75Fu term is an adjustment for the effective actual area versus the gross area. That 0.75Fu will be further adjusted by a safety or resistance factor during your design. A325 and A490 only come in heavy hex bolts. They are not available under those standard for a threaded rod product. Note that F1554 also comes in 55 ksi and 105 ksi yield grades, although I don't know the relative availability of those grades as the majority of people are going to be using the Grade 36 material.
An upset rod is where you use a smaller diameter raw stock and then form the threads into it which will expand the thread diameter up to the nominal rather than screw cutting the threads into a full nominal base stock. Researchers have concluded that the upset threads have actually better thread capacity than cut threads as the molecular composition of the steel is more intact without the cutting. When figuring tensile strength of the rod away from the threads you would need to use the diameter of the base stock. For a fully threaded rod, the upset option is not really available in my opinion. If you are only forming 6" of thread or so on the end of the rod then it makes sense.
The best source for the yield and/or tensile strength is going to be in the ASTM document. This is assuming that the raw stock is intended to be a structural grade material rather than a material that is rated more on its formability. Structural grade materials are required to meet certain yield, tensile, and elongation properties. For the formability grades any published information regarding yield, tensile, or elongation is going to be non-mandatory target values and the supplier would typically not actually test the material for yield.

 

[wannabeSE]

Table 2-6 in the Steel Construction Manual list the tensile stress of some common fasteners including A193 Gr B7. This table is also printed in a Modern Steel article, Are You Properly Specifying Materials:

http://msc.aisc.org/globalassets/modern-steel/archives/2015/02/steelwise.pdf

 

[BSVBD]

ajh1: Thank you for your helpful information and insight.

wannabeSE: Thank you for your resources. Table 2-5 is the credible reference I was looking for.