Calling out standard bolts on drawings & bolt certs
Calling out standard bolts on drawings & bolt certs
(OP)
In our work we usually (pretty much always) deal with NAS fasteners and so we are use to having a very specific fastener code to place on drawing EPLs to allow the shop to order the exact fastener we need from any number of industry vendors. We are now designing a piece of tooling and are wanting to use standard Grade 8 bolts. We are struggling to find any part numbers or standardized "codes" to place in the parts list to indicate a specific fastener. I know the bolts (for example) are SAE J429 Grade 8 bolts (which use dimensions from ASME B18.2.1). I have tried to describe the bolt like follows:
SAE J429 GR8, 1.0-12X3.0
But the shop says this is not specific enough for them to order a fastener. The only thing left I can think to do is narrow it down to a vendor and use their unique product ID/SKU number on the EPL, but this removes flexibility for the shop to be able to use other vendors if they are out of stock or find a lower price (without having to rev the drawing to change the code or approve an alternate). I am wonder what other engineers/fields do to call out "normal"/Grade 8 bolts that do not have a standardized coding system similar to NAS.
In a related question; we do not need the traceability of the NAS bolts, but are not sure if there are options where we can get some intermediate forms of certification (lot certs, etc) that satisfy that the fasteners meet at least basic material and strength properties and that they are not forgeries. I was around at a past job when this issues was dealt with and solved, but I was not directly involved so I may not be remembering the terminology or describing it 100% accurately. Does anyone know what I am trying to describe in terms of something between a NAS bolt and grabbing something from a bulk bin at a hardware store? We are trying to not get pushed into two extremes where it is either full certs or no certs at all.
SAE J429 GR8, 1.0-12X3.0
But the shop says this is not specific enough for them to order a fastener. The only thing left I can think to do is narrow it down to a vendor and use their unique product ID/SKU number on the EPL, but this removes flexibility for the shop to be able to use other vendors if they are out of stock or find a lower price (without having to rev the drawing to change the code or approve an alternate). I am wonder what other engineers/fields do to call out "normal"/Grade 8 bolts that do not have a standardized coding system similar to NAS.
In a related question; we do not need the traceability of the NAS bolts, but are not sure if there are options where we can get some intermediate forms of certification (lot certs, etc) that satisfy that the fasteners meet at least basic material and strength properties and that they are not forgeries. I was around at a past job when this issues was dealt with and solved, but I was not directly involved so I may not be remembering the terminology or describing it 100% accurately. Does anyone know what I am trying to describe in terms of something between a NAS bolt and grabbing something from a bulk bin at a hardware store? We are trying to not get pushed into two extremes where it is either full certs or no certs at all.





RE: Calling out standard bolts on drawings & bolt certs
Dik
RE: Calling out standard bolts on drawings & bolt certs
I occasionally have this problem as well, and have found that different fastener manufacturers have traceability schemes different enough that if you switch suppliers you lose the traceability you were going for.
In short, if you want even a modicum of traceability, just pick a manufacturer and specify their part number.
RE: Calling out standard bolts on drawings & bolt certs
Regards,
Mike
The problem with sloppy work is that the supply FAR EXCEEDS the demand
RE: Calling out standard bolts on drawings & bolt certs
Ted
RE: Calling out standard bolts on drawings & bolt certs
The problem with sloppy work is that the supply FAR EXCEEDS the demand
RE: Calling out standard bolts on drawings & bolt certs
Regards,
Mike
The problem with sloppy work is that the supply FAR EXCEEDS the demand
RE: Calling out standard bolts on drawings & bolt certs
I hadn't checked into A-193 bolts, but they do look to have a shade less tensile strength than Grade 8 and we are very tight on margin at this joint. We could also only use the B7 variety because we are only permitted to use certain grades of stainless steels.
In light of not having a common certification system or standards to reference, we would probably be OK with going to a single supplier (and approving deviations as required). It appears the shop just wants to place an order based on specific numbers/product codes and not have to do any thinking when placing the order. They want something that lays out every possible dimensions/option/coating/etc. to the T so they can give us exactly what we think we are getting. They want nothing to do with selecting the fastener or having any options to chose from. The cert thing is completely self-imposed by engineering that we want to make sure we are not buying fakes or something and that we have some proof the bolts are what they say they are material/strength wise.
I'm trying to get them to document their needs as we speak. They currently have one of their planners submitting RFQs to see what they could find so they could feed back the info to us (but they are just looking at local suppliers as far as I know).
RE: Calling out standard bolts on drawings & bolt certs
RE: Calling out standard bolts on drawings & bolt certs
RE: Calling out standard bolts on drawings & bolt certs
People in H3ll want ice water :)
Regards,
Mike
The problem with sloppy work is that the supply FAR EXCEEDS the demand
RE: Calling out standard bolts on drawings & bolt certs
Does that mean they also won't inspect samples from the lot they receive, or examine the paperwork that's included? Then for peace of mind...
Myself, I've had to accept that the purchaser probably doesn't know anything about the parts on the drawing. They're just names and numbers to some of them. We have some clever purchasers and planners who know what these things are, but we also have some who don't.
STF
RE: Calling out standard bolts on drawings & bolt certs
How would they begin to approach that? "SAE J429 GR8, 1.0-12X3.0" calls out one of multiple fasteners somewhere described in one of multiple standards.
RE: Calling out standard bolts on drawings & bolt certs
That is all that is needed to get the correct item.
That is why that "laundry list" is there.
= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube
RE: Calling out standard bolts on drawings & bolt certs
As far as lot control, that will depend on your vendor. These will probably be off the shelf parts and so you will need to find a vendor who will provide you with material and HT certs, along with a COC. For commercial, standard parts, that is going to be about the best that you can hope for unless your volume is great enough to get a production run going and then you can get whatever level of certs that you want(for a cost).
RE: Calling out standard bolts on drawings & bolt certs
They will do CVT testing on the delivered lot and test samples (since we are telling them to). I am sure they would gladly not do it to save themselves effort. The included paperwork is one thing I am trying to determine that we make sure we get, so we have something to examine.
It sounds like if we order to the J429, then that means it should come with certain items (I'm reviewing the standard again as we speak), and depending on the vendor they may have additional paperwork that we can review as well and we just need to verify and set this up front as a requirement. It appears to be a "lessons learned" thing that the last time the shop bought non-NAS bolts they ran down to the local fastener store and got some bolt that were advertised to meet some standard and didn't get any paperwork with them, so we couldn't verify the end item. The question is more making sure we get the paperwork to validate the bolts conform to J429 and we will be good to go.
RE: Calling out standard bolts on drawings & bolt certs
Suppliers like McMaster-Carr will provide fasteners in sealed boxes along with certs if you want.
RE: Calling out standard bolts on drawings & bolt certs
Ironically, in my opinion calling out a single fastener like this it is even MORE restricting to them than a NAS-type fastener (should still be a lot cheaper though I hope), but it does remove all ambiguity.
RE: Calling out standard bolts on drawings & bolt certs
Its generally considered bad practice and I would caution against adding supplier p/ns to any print or internal system, you want the suppliers making, purchasing ordering, and quality teams accepting parts to YOUR spec, not theirs which is guaranteed to change over time independent of you.
RE: Calling out standard bolts on drawings & bolt certs
Tunalover
Electro-Mechanical Product Development
UMD 1984
UCF 1993
RE: Calling out standard bolts on drawings & bolt certs
RE: Calling out standard bolts on drawings & bolt certs
RE: Calling out standard bolts on drawings & bolt certs
I already said that VICDs have performance and inspection requirements that are verified by incoming QA. If your QA isn't doing this, they are the ones putting the company at risk. As for losing sales, 100% of the time procurement will know, and have the most external connections, so they can leak that info. Not using VICDs is not going to stop that.
Perhaps your company has been misusing VICDs, which is the most likely explanation. If you have leaks in the organization, someone will leak the entire drawing package along with the buying history.
RE: Calling out standard bolts on drawings & bolt certs
The main issue has remained that our shop demanded unique and exhaustively specific codes/product for every individual product/fastener they had to buy. We actually did try to use the ASME ordering code system, but found the suppliers didn't really know what to make of it.
Ex, our shop wanted:
xxxxxxx = SAE J429 GR8, 1.5-12X3.0 UNF-2A cap screw, zinc plated
yyyyyyy = SAE J429 GR8, 1.5-12X4.0 UNF-2A cap screw, zinc plated
zzzzzzz = SAE J992 GR8, 1.5-12 UNF-2B nut, zinc plated
wwwwwww = SAE flat washer, zinc plated
...
For each of the dozens of different common fastener line items we were needing they required a single part "number" to order to.
The only way the team could find to do this was as mentioned, to select a particular vendor and use their internal product codes and a "supplier" column on our EPL. This doesn't make much sense to me as it defeats the point of using a "common" fastener by specific it must be bought through this one vendor. Our management was ok with having to spend the engineering time to change the drawing if they needed additional fasteners in the future and needed to use another vendor. Every time we need to add a fastener or vendor, we are going to just add a new product ID and vendor as an alternate. This is made worse as in this situation we were very limited what drawing and release options we could use because of some special tracebility requirements on this project and rules not allowing us to "reassign"/"renumber" commercially sources parts unless we modify them, and our quality not allowing any substitutions without it being on the drawing. (we used to have an "or equivalent note" that allow us to approve a different fastener than initially selected).