Component Drawing Raw Material Location 1

[mdombovy]

Hello All,

Looking to get some feedback. I have a coworker who is raising an issue with component drawings not listing the raw material they are made from in a tabulated Bill of Materials on the drawing. I explained to him that our drawing template has a location for this material in the title block and that if it needed more definition, we would do so in the notes. I further explained that Bill of Materials on engineering drawings are generally for tabulating lists of parts/components used to make a sub-assembly or final assembly. It would seem unnecessary to include a Bill of Materials for the one raw material used to create a component. I briefly searched through ASME standards and could not really find anything.

Has anyone seen a component/part drawing that includes of Bill of Materials table just to show the raw material it is made from?

Thanks in advance!

 

[TheTick]

The less information pushed up into assembly drawings, the less likely they will require revision.

People are lazy and want everything they need to be in one place at one glance. So there are always people lobbying for "their" information to be crammed on to drawings to save them the pain of looking up things they should probably already know (or at least know how to find).

Does material belong on an assembly drawing? I say no. But, really it depends on standards and policies. Unfortunately, drawings often become a "junk drawer" of info-bits placed to appease every reader that may encounter said drawing.

 

[jassco]

Hi, mdombovy:

I agree with your coworker. If you have a print for your component, it needs to define material of this component on the component drawing. The same material description can be displayed on other prints. But they are only for reference.

Best regards,

Alex

 

[3DDave]

The only time I would have material on a drawing like that is for items like weldments or other inseparable assemblies where the component dimensions are not specified in favor of finished item dimensions.

Were I to want to weld a frame that has to be 24 inches X 24 inches (within some tolerance) outside dimensions then I don't want to include the tolerance on the tubing or on the weld-prep, et al. There is no reasonable way to ensure that the final tolerance can be met without the welder grinding or otherwise adjusting the lengths of parts in a way that cannot be represented if the individual parts were cut and inspected. Further, being a weldment, many of the part surfaces will be obliterated by the weld process and no longer can be confirmed as meeting an original requirement - just the overall dimensions.

Weldment - yes to a Bill of Materials tabulation (it's also a component tabulation)

Individual machined part? Typically that only needs a Parts List if there are threaded inserts or other inseparable items, but those small parts are rarely fabricated per the individual part drawing where they are installed.

 

[mdombovy]

All,

I think I may have been a bit confusing in my initial post.

The drawing in question is not an assembly drawing. It is a drawing for a part made from one raw material (SS bar milled into designed shape). From my experience, the material on this type of drawing would fall into the title block or be more defined in the notes if needed. My coworker was having issue that the material was not inside a tabulated Bill of Materials just of above the title block which I think is rather unnecessary on component drawing and quite frankly, have never seen it done that way.

For clarification, the material is already/controlled on the drawing. It is located in the title block instead of an additional Bill of Materials table (my coworkers preference).

 

[jassco]

Hi, mdombovy:

A component should not have a bill of material unless it is made of multiple components or materials.

Is it true that your coworker wants to show material description in two separate places on the same component drawing? If that is case, then he is wrong. You should not show material twice on the same drawing.

Best regards,

Alex

 

[mdombovy]

Hi Jassco,

I do not think he wants to show it in two places but would prefer that its shown once in a bill of materials.

I appreciate all the feedback.

 

[ctopher]

All that is needed is a note on the drawing showing what material made from and material spec as needed. From my experience, adding material to a BOM is not needed. If the material is changed, the BOM needs to change. The BOM is for ordering parts to make an assy.
The dwg indicates the material for the machinist to work to.

Chris, CSWP
SolidWorks
ctophers home

 

[jassco]

Hi, mdombovy:

BOM is defined for assemblies with multiple item.

A component made from a material or another component does not have BOM. Do you show BOM for a single component?

If a component is made from another components or multiple components, it can have a cut-list.

It is optional to show materials in BOMs or Cut-list.

Best regards,

Alex

 

[ewh]

I have seen this practice before (single component BOM) but not often. It was company standard (for someone's convenience) and would not appear in the ASME standards. It can get really silly if you use separate BOMs.
I had no issue with it as it was a blanket policy and no different to me than placing the material in the notes (my preference). There would be confusion though if it were not uniform across all detail drawings.

"Know the rules well, so you can break them effectively."
-Dalai Lama XIV