-100, -300, and -500 Drawing Levels

[BrysonRD]

I used to see drawings with -100 level sub-assemblies that fed into -300 level sub-assemblies which in turn fed into -500 level sub-assemblies. It seems like these were on Boeing and Northrop drawings, so maybe it's more of an aerospace industry practice. I've tried searching for this using different terminology, but I can't find anything related to this style of drawing.

Does this sound familiar? Is there a specification that lays this out, or is it more of just an "acceptable method" that some companies have chosen to adopt? If anyone could point me to some documentation that would be greatly appreciated.

Thanks in advance.

Bryson

 

[MintJulep]

Get yourself a long rope and tie off to a big tree.

Then Google for intelligent part numbers.

Good luck finding your way back out of the rabbit hole.

 

[BrysonRD]

Thanks, but this isn't what I'm looking for. We use intelligent part numbers already.

I'm wondering about the method of using different levels within a single drawing for sub-components or sub-assemblies. It allows for a way to reference an interim item that doesn't have a part number that is fed into another assembly.

This can be used on large or assemblies or weldments. For a simple example, P/N 39280381 is an assembly. It is a piece of sheet metal that is cut to size and bent, then some press in fasteners are added. The method I'm trying to think of allows for the interim piece of cut sheet metal to be given the pseudo P/N 39280381-100. There can be other layers to the assembly that would use -300 and -500. It's been a while since I've seen this, so I'm not even sure I'm describing it correctly. Just trying to remember the name of the method...

Thanks

 

[drawoh]

BrysonRD,

Are you fabricating your sheet metal pieces in-house?

Most of my fabricated parts in SolidWorks are modelled as assemblies. This makes it easy to insert PEM[ ]nuts, helical thread inserts, dowel pins, etc. The drawings go out to our sub-contractors with what I call Material Lists of stuff the contractor will order, stock and install. The inserts do not appear on my assembly BOMs. Our purchasing is only responsible for the fabricated and assembled part.

Why can't you use the drawing title to distinguish what the part is?

--
JHG

 

[BrysonRD]

I don't actually have a sheet metal part at the moment. That was just an example--maybe a bad one.

It seems to be an industry acceptable "standard," but I can't find any documentation about it.

The attached image is from a Lockheed drawing. The 301 and 501 assemblies would not be in the ERP. They are just a way to reference a sub-assembly within the drawing.

 

[drawoh]

BrysonRD,

To me, a subassembly is an assembly that is called up by another assembly, and nothing more. On my main assembly BOM I see a part number. When I need to order, I pull out the documentation. If this turns out to be another BOM, I order everything on the BOM. Your MRP/ERP software has the ability to generate indented BOMs, showing the contents of all the subassemblies.

I don't care at what level the subassembly is called up. If the part has a BOM, it is an assembly, and somebody has to put it together.

If my subcontracted, fabricated part has more than one piece, there is a material list on the drawing which is invisible to our MRP/ERP. The vendor has his own supply chain. Either your vendor can fabricate your part, or they can't. Maybe they don't do helical thead inserts. Maybe they don't do accurate tolerances.

--
JHG

 

[jassco]

Hi, BrysonRD:

Those are just numbers for items. You can use any numbers you want to as long as they don't cause duplicates.

-100, -300, and -500 are an old school way to create intelligent item no. They are good for easier recognition by humans, but no good for automation.

Alex