ifitgoesfast

I've always been curious if the various GM/Chevrolet models within same year shared bolts (and other fasteners), or were the bolt sets unique to the model. Logically, it would make sense for GM to contract/manufacture them in bulk for all models depending on specs needed for usage whether base, HD, or SHP regardless of model. Anyone know?

Nowhere Man

Most common bolts are shared if in the same usage gm had at least 8 diffreant bolt suppliers

ohiovet

I think that GM outsourced most of their fasteners so they would probably be considered a commodity product.
Therefore they could have been used across different product lines.
Although each assembly plants inventory might have been controlled by that individual plant.
We need a GM guy to elaborate on this.

MikeM

GM published a library of books outlining GM engineering standards for standard hardware parts like clevises, ball joints, grommets, gaskets, tire valves, screws, nuts, pop rivets, bolts, etc. You get the idea.

The standards described the parts length, width, thread pitch, I/D, O/D, finish, etc., and GM parts numbers were assigned to each part.

A design engineer could go to these books, pick a part that he wanted and assign that part, by GM part number to his drawing.

I have three of these books out of a complete set of ????. Wish I had the full set as you can look up any standard part by GM part number and get a complete description of the part.

Somebody else that windier than I am could offer a better explanation of these books.

tuxnharley

That sounds like a personal problem, Mike!

426 Hemi

It would be interesting if come to find out the FP air cleaner bolt was also used on say, a '67 four door Nova--- rear door glass regulator bracket.

MikeM

If you have access to the GM parts system, you can search a specific part number and it will show model usage. At least it has the few times I've used it.

Bill32

All the large manufacturers do it. It's simply economics.

I was a design engineer for Ingersoll-Rand. I used the "Corporate Standards" books (it was mandatory).

You have a large company like IR or GM with thousands of engineers using in a 3/8ths by one inch bolt on hundreds of projects.
You could end up with a thousand part numbers for the same bolt.
That would cost a lot of $$$. Purchasing would have to buy 10k of one part number and 10k of another part number for the same bolt vs. 100,000 with all being under one part number (quantity discount).

Engineering would provide a list of approved vendors for that bolt to purchasing. Approved vendors would have different head markings on their bolts unless specified on the engineering drawings.

When you're designing, you try to stay away from any specialty bolts unless absolutely necessary.

DansYellow66

I would guess some of the drivetrain fastners (engine, transmissions, maybe some rear ends) might be shared across Chev model lines for any given year.

W Guy

What was the original p/n for that bolt?

Verne

JohnZ

Design engineers consulted with Fastener Engineers very early in the process to either select the correct existing fastener for the job (from the GM Standard Fastener books MikeM mentioned), or to have Fastener Engineering design and develop a new fastener. Any engineer who released a new part or assembly without Fastener Engineering sign-off first which later required a fastener change just made a career-limiting decision.

W Guy

Mike,
One way I've found to cross-reference a part's application is with a price book (back when they still used books!) In those books, a part number will list the group numbers where that part has an application. Then with a parts book (actual printed media again) it's easy to find each application.
I also have a "Standard Parts Catalog" that lists all the hardware, noting sizes, head type and finish. Many of those listings also list the group number where it was used. That catalog also lists chemicals & lubes, electrical sockets & plugs, fuses and bulbs.

Verne