SB-473 N08020

[SnTMan]

Fellow engineers,

Anybody know of any basis permitting the use of this material for Sec VIII, Div 1 bolting?

Obviously it is not present in Sec II, part D Table 3, as required by Part UNF, UNF-12.

Thanks in advance,

Mike

 

[TJOrlowski]

I don't think so, Alloy 20 isn't even listed under another specification in II-D-3.

Can you substitute with something close, composition wise?

-TJ Orlowski

 

[SnTMan]

TJO, first, thanks for the reply.

My library of Interpretations and Code Cases going back is pretty skimpy, was hoping to perhaps find one or the other.

If no basis exists to use the N08020 for bolting we will have to substitute. Complicating factors: This material was a customer request, one job (two units) is in the shop now, any bolting purchased will have to be discarded. It ain't cheap. A new order is on-line, but nothing is done yet, so we're OK there.

This is one of those things, nobody bothered to check it out even though somebody suggested that this be confirmed as a permitted material.

Will see if any further info comes along.

Regards,

Mike

 

[SnTMan]

And of course, the software didn't object.

 

[TJOrlowski]

$16.00/lb, with about 15 lbs req'd per bolted joint (assuming you're using 1" round bar to make your studs). A couple of bolted joints per unit, over two units - yeah that's nothing to scoff at if you're just putting it on the shelf to never be used again.

I can imagine where you're coming from: The customer spec'd the material, the estimator/salesman quoted it, you won the PO, the engineers drew it and generated Code calcs. The AI wasn't in that day, and wasn't scheduled for the next few days, but everything on the calcs looked OK, so the drawing (calling for Alloy 20 bolts) was submitted to the customer. The customer approved it. Now the AI is going doing the initial review of the approved for fabrication job (where material has already been purchased against the BOM) to set hold-points etc and there's a discrepancy.

Those jobs tend to stick out in one's memory.

Back to actually dealing with the problem: have you discussed with your AI finding tensile and yield strengths for the bolts you're buying/making by getting them tested, to validate that their strength meets or exceeds the values used in the calculations? If you can show empirically that the studs/bolts are strong enough for the flange(s), I would hope that would satisfy the Code, and the AI.

-TJ Orlowski

 

[SnTMan]

TJO, the scenario is pretty much as you described it.

I don't know whether the AI has noticed this or not. These jobs are being built in one of our plants in another city. We (I) just became aware of the situation yesterday in reviewing the new job.

I don't know if our AI would be receptive to your course of action or not. Of course, I suppose now we need to decide how to proceed on the new order as well. Do we tell the customer we can't use the N08020 on the new order? Then how did we use it on the previous order?

Fortunately this is not primarily my problem to solve. However, anything I can learn that may help, could, you know, help.

Thanks,

Mike

 

[stanweld]

SnTMan,
Perusing through the current Code Cases, NO8020 is not listed therein. Code Case 2526 (NO8367) may prove a good substitute.

 

[SnTMan]

stanweld, thanks, I see that N08367 is listed in Table 3. I will mention it if I become further involved.

What does Code Case 2526 address? Does it perhaps pre-date the 2010 edition?

Regards,

Mike

 

[SnTMan]

Never mind, I just looked it up on the ASME website