【转帖】parts list question

yang686526

parts list question
i'm having a bit of a discussion with another engineer, regarding which should be used in the parts list/balloons on a drawing.  he uses numbers for pieces in a weldment, and letters for assembled items (anything that can be removed in a non-destructive way).  this results in some drawings having two parts lists, if they contain both welded, and assembled items.
i use numbers for everything, and only one parts list.  i reserve letters for datums.
is there an asme standard, that defines any of this?
thanks,
  dave
-dave
everything should be designed as simple as possible, but not simpler.
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off of the top of my head, i would agree with his method because the weldment is actually a sub-assembly.  i would use letters for the weldment details and numbers for the main assembly, however.
the ambassador and the general were briefing me on the - the vast majority of iraqis want to live in a peaceful, free world. and we will find these people and we will bring them to justice."fff"> - george bush, washington dc, 27 october, 2003

it's going to depend some on how your drawing is structured.
for us we wouldnt' have this problem as the weldment would probably be it's own drawing & other items would be assembled at the next level.
asme y14.3m-1996 only talks about number, see figure 4 on page 6, first paragraph.  it's called a find number.
so of the two methods i'd say you're probably more correct.
i thought 14.100 had some stuff on this but couldn't find it when i looked.
kenat,
the method i have used in the past is to have an indented parts list, using numbers for everything.  as kenat infers, it is usually better to have separate drawings.
the ambassador and the general were briefing me on the - the vast majority of iraqis want to live in a peaceful, free world. and we will find these people and we will bring them to justice."fff"> - george bush, washington dc, 27 october, 2003

i have always used numbers and have never seen letters used anywhere for "find numbers" or balloons associated with pls.
you can search for more info here:
i've seen combination letter & number on electrical stuff but that's a bit different.
kenat,
separate drawings would be my preference too.  that should be be my argument, and not letters vs. numbers.
i've also seen/used indented parts lists in the past too, but i believe inseperable assy
thanks for the info.
-dave
-dave
everything should be designed as simple as possible, but not simpler.
the inseparable components all have the same part number but each component has a sub number. all the other components just have a top level number.
find #| description
1.1   | weldment member 1
1.2   | weldment member 2
i've worked for a few small machine design companies (custom designed and built machines) and we used both letters and numbers in the bom / parts list.  the numbers were the fabricated parts (used by the machine shop for part and drawing inventory, material ordering, etc.) and the letters for purchased components (used by the purchasing department for ordering)
this also informed whoever was assembling / managing the project where they should be looking for the parts.  letters told them to go to shipping and recieving.  numbers told them to go to the machine shop.  most of the time, it was a case of walking around with the assembly print(s) and looking at/for all the various parts.
"#1-5 are still being black oxided, #6-8 will be completely machined by tomorrow morning, a thru d are in the... wait, where's the 3rd pnuematic cylinder?"
considering that this was in companies that may have 12-20 projects in various stages... and the building was not very big (1/4 size of an average walmart), it worked quite well.  however, it was strictly an internal standard, not anything nationally / internationally recognized.
"a designer knows that he has achieved perfection not when there is nothing left to add, but when there is nothing left to take away"  - antoine de saint-exupry