CELinOttawa
Structural
- Jan 8, 2014
- 1,456
Hello All,
Long time reader, first return post. Long story, not germane to the issue. Need some opinions...
I did a design using A307 threaded bar, knowing the fabricator and their source of stock. I specified A307 Gr A, S1, as I needed weldable. The City's engineer checked the design and said that: 1) 1 1/2" x 1/4" HSS was not in the steel manual. 2) The drawings were in colour and as such were unclear, must be resubmitted in B&W. 3) The threaded bars were overstressed.
I sent in a set of our calcs. No dice; City refused to review them. I sent the local steel stockists list in to show the availability (and indeed existance of the HSS). I redid the drawings in B&W. Not worth the fight. I answered a laundry list of questions. Still no good.
After all of that the City's engineer kept asking cagey questions about the stem bolts. Finally I typed out the pertinent section of our calcs. He came back and said that the yield strength for Grade C A307 is 36ksi. I explained that no one makes threaded bar in A307 at all (it is ALL co-graded), and that Grade C hasn't been available in years and years, and was in fact removed from the standard in 2007. I explained that I used SAE Gr 2 yield as the bars as known to be produced to both standards. A307 Grade B is the exception, as it requires a maximum breaking strength for use with cast iron pipe fittings where they want to ensure the stem bolt fails before the end fitting.
SO: After all of that, the City's engineer asked me to add the 60ksi minimum to my drawing. So I did. Then he insisted that I remove the reference to A307. I pointed out that the A307 A S1 was how I was ensuring my code compliant weldability. He said he didn't care, he just would not permit the job with A307 shown. I pointed out that adding a minimum (which I know for a fact I would get) does nothing to counterman the A307 reference, and all of this despite A307 A / SAE Gr 2 being the only available product (See any bolt supplier's threaded rod products and you'll see what I mean. Portland bolt uses the exact same stock number for both "products". It is all now co-graded). SAE Gr2 bolts are dangerous crap, but the same is simply not true of the threaded bar thanks to the pragmatism of making the Gr 2 bars also meet A307.
Here comes my question. Our profession holds us to the standard of what a similarly trained and qualified engineer would have done. An almost impossible threashold to measure, but I am going to appear to the courts of Internet Engineer Opinion (hereafter IEO, j/k). Would you do what I did? Am I wrong to rely upon a known yield strength that comes from a non-referenced standard?
In the end, we agreed upon "Threaded rod shall be min Fy=60ksi yield and weldable without affecting the yield strength.". That's going to be the same bar (cograded, weldable A307/SAE Gr 2. I know the stock and have the mill certificate. The design has not changed, not one screw or bolt. It is just four times the cost to the client. Thank GOD this isn't a fixed fee engagement!
Thoughts? That's enough venting for one day... Apologies to all.
Long time reader, first return post. Long story, not germane to the issue. Need some opinions...
I did a design using A307 threaded bar, knowing the fabricator and their source of stock. I specified A307 Gr A, S1, as I needed weldable. The City's engineer checked the design and said that: 1) 1 1/2" x 1/4" HSS was not in the steel manual. 2) The drawings were in colour and as such were unclear, must be resubmitted in B&W. 3) The threaded bars were overstressed.
I sent in a set of our calcs. No dice; City refused to review them. I sent the local steel stockists list in to show the availability (and indeed existance of the HSS). I redid the drawings in B&W. Not worth the fight. I answered a laundry list of questions. Still no good.
After all of that the City's engineer kept asking cagey questions about the stem bolts. Finally I typed out the pertinent section of our calcs. He came back and said that the yield strength for Grade C A307 is 36ksi. I explained that no one makes threaded bar in A307 at all (it is ALL co-graded), and that Grade C hasn't been available in years and years, and was in fact removed from the standard in 2007. I explained that I used SAE Gr 2 yield as the bars as known to be produced to both standards. A307 Grade B is the exception, as it requires a maximum breaking strength for use with cast iron pipe fittings where they want to ensure the stem bolt fails before the end fitting.
SO: After all of that, the City's engineer asked me to add the 60ksi minimum to my drawing. So I did. Then he insisted that I remove the reference to A307. I pointed out that the A307 A S1 was how I was ensuring my code compliant weldability. He said he didn't care, he just would not permit the job with A307 shown. I pointed out that adding a minimum (which I know for a fact I would get) does nothing to counterman the A307 reference, and all of this despite A307 A / SAE Gr 2 being the only available product (See any bolt supplier's threaded rod products and you'll see what I mean. Portland bolt uses the exact same stock number for both "products". It is all now co-graded). SAE Gr2 bolts are dangerous crap, but the same is simply not true of the threaded bar thanks to the pragmatism of making the Gr 2 bars also meet A307.
Here comes my question. Our profession holds us to the standard of what a similarly trained and qualified engineer would have done. An almost impossible threashold to measure, but I am going to appear to the courts of Internet Engineer Opinion (hereafter IEO, j/k). Would you do what I did? Am I wrong to rely upon a known yield strength that comes from a non-referenced standard?
In the end, we agreed upon "Threaded rod shall be min Fy=60ksi yield and weldable without affecting the yield strength.". That's going to be the same bar (cograded, weldable A307/SAE Gr 2. I know the stock and have the mill certificate. The design has not changed, not one screw or bolt. It is just four times the cost to the client. Thank GOD this isn't a fixed fee engagement!
Thoughts? That's enough venting for one day... Apologies to all.
