Part Numbers & McMaster-Carr

[leeave96]

McMaster-Carr has a gizzion parts in their catalog. Rather than use an internal company part number, ex. 123456 for a part and then reference the McM part number, has anyone used the McM part number itself?

For example, one has a bolt with a given thread, material and coating. What if you simply used the McM part number for that item and IF (as an example) someone wanted to buy it elseware, then they would have to buy a part that is form, fit and functionally the same as McM.

Further, the McM part number would be used as any other part number in bill of materials.

This would eliminate taking out part numbers internal to your business, saving time and by using the McM numbers, would also nail down the specifics of the part, again without creating some type of source control drawing.

Anyone do this or given it a try?

Are McMaster-Carr part numbers stable enough over time to allow this without screwing-up everything down the road?

Just courious.

Thanks,
Bill

 

[MadMango]

The problem with your example is that most of the hardware from McMaster is for a unit of issue of more than EA. If you buy a box of 25 bolts, and use only 2 of them, would the unit of issue in your BOM be .08 or 2? If 2, what happens to the other 48 bolts? How is the production floor to know what .08 actually is?

You can never know when McMaster will change or modify their numbering system. Relying on it for your future production needs would be a bad item. It doesn't take long to cut & paste their drawings into your drawing templates and assign new numbers.

"Art without engineering is dreaming; Engineering without art is calculating."

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[KENAT]

So MM makes a good point on the qty, though I would hope you could overcome this - if it's clear that the MM number is being used to functionally define the part not to order against.

Parts may change over time, obviously this will be worse for things that aren't already to some industry standard. For instance I'd expect most standard fasteners to be fairly stable - however that doesn't mean McMaster couldn't change their numbering system and screw up all your drawings.

Of course, if parts are nominally to an industry or national standard why not directly reference that standard as is often done with MS & NAS parts etc.

The idea of cutting & pasting every nut, bolt & fitting etc. has a significant time implications. While Source or Vendor control drawings have their place, they don't come free.

If your equipment has long lives, or if you have regulatory compliance issues it's probably not an option to reference part numbers from a catalogue completely beyond your control with no back up data.

However, if you historically half ass it and don't really robustly define non drawn items at least it's a step in the right direction.

My employer falls in the latter category. On 'inseparable assemblies' and the like we will just reference the MM part number for things like press fitted pins.

On regular parts in assemblies, we still allocate an internal PN (so we can gouge the customer on spares) making a PDF copy of the data on McMaster at that time to serve as our documentation and filing this in our data storage area under out PN.

However the extra thing we do to allow sub contract assembly, is add 2 columns to our parts list ‘manufacturer PN’ & ‘Remarks’. In the drawing parts list we show the Mcmaster or similar PN in the ‘manufacture PN’ column (I know technically they aren’t a manufacturer but close enough for most of our needs) and add the manufacturer name in the remarks column (we use cage codes some but a lot of folks don’t understand them). This is because our SAP implementation limits us to 40 character for part description else I’d just put that info in the description field.

This is not a perfect system, however so far I don’t think it’s caused any disasters. We’ve recently been adding the McMaster info to a lot of hardware that we used to just rely on describing with text. Our descriptions, especially when abbreviated to 40 characters, weren’t always robust enough for our subcontract assembly partners.

So, it's not a great idea, but depending on your circumstances may be adequate - or at least better than what you do now.

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[MikeHalloran]

My last employer used _everyone_ else's part numbers.

It didn't cause any major problems of and by itself, but they starting doing it in the '70s, when their brain- damaged computer system couldn't deal with all the characters that might appear in a part number, and was so expensive that they had to severely limit the size of the part number fields.

They've replaced the hardware several times, but the software is still the same old POS, and still brain- damaged. So you can search for a part by description, find the part, then search using the transmogrified part number that's in the system, and _not_ find the part. But that's an artifact of how the POS system was implemented, not an effect of using external part numbers.



Mike Halloran
Pembroke Pines, FL, USA

 

[ptruitt]

I'd recommend against it. As a designer, I try to lead the organization away from source-controlled specifications. When you have an internal number cross-referenced to a supplier's part number, you have the opportunity, when things are slow, to write an interchangeable change order to replace the supplier's part number with an internal specification so that Purchasing can look around for the lowest cost.

 

[KENAT]

At our place, in practice, they don't stick to the exact McMaster part, they'll contact their preferred widget vendor and say they need something equivalent to the Mcmaster PN.

In fact, on some newer drawings etc we've aded 'OR EQUIV' against some items to explicitly allow this.

As I said before, not as robust as maybe required in some industries, and not ideal, but maybe better than what you already have going on.

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[SnowCrash]

Mcmaster often changes part number/catalog numbers. Similar part numbers can yield different parts when they buy from different vendors. Don't trust the details.

--
Hardie "Crashj" Johnson
SW 2010 SP 2.1
HP Pavillion Elite HPE

 

[gmarken]

My company has been using McMaster-Carr numbers. It is so easy to download a model from the website and drop it into the assembly. We use the BOM that Inventor creates so the McMaster number appears automatically. So far we have not had any problems with part numbers changing.

 

[looslib]

If you use a generic description and a company specific part number, where does the customer have to go for spare parts? Back to the original supplier, who can sell spares at a slight markup; buying a box of 100 bolts costs $.06/ea but as a spare is sold for $.10 plus a flat shipping charge.

We used to do the same thing in an auto delaership parts department. Oil filters were bought for $2.24 from a third-party, not the car maker's spare parts department for $2.92, and sold out at $3.40, even though the MSRP ws $3.28.


"Wildfires are dangerous, hard to control, and economically catastrophic."

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[KENAT]

This is why we assign company part numbers to fasteners etc.

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[apekim]

We currently use vendor part numbers in our models and in our parts lists (bom's). In my opinion, it is NOT the way to go.

I am fairly new to this organization (3 years), and I have questioned others of the initial intent of this decision to use vendor part numbers. For the most part is was chosen for 3 reasons: 1) To eliminate the need to create a source control drawing. 2) To eliminate the need to pull a company part number. 3) So that the vendor p/n will appear on the parts list (not a non-intelligent company p/n).

These are not good reasons since you really do not need to create SCD's for cross-referencing vendor numbers to company part numbers. If set up properly, it takes no time to pull a company part numbers. As far as the parts list goes, you can add columns as needed to your parts list...so you can have vendor p/n's and company part numbers on your parts list in different columns.

Don't do it, you will be sorry.