bolt/nut/etc callout

[Howard M.]

Is there a document that translates the assembly instruction bolt, nut, screw, etc. callout (such as: 122320 Bolt) to physical characteristics of diameter, thread, length, type? Thanks.

[Chris H.]

Re: bolt/nut/etc callout

Yes, a great big binder used to sit on my desk at GM. Do not know what happened to them. Now that everything is on line at GM they are no longer used.

Chris

[Geoff C.]

Re: bolt/nut/etc callout

Chris
Are you referring to the Standard Parts Book or a different book?
Geoffrey Coenen

[Chris H.]

Re: bolt/nut/etc callout

I am pretty sure this was a GM internal book put together with just nuts/bolts/screws. It had info in it like sizes, finish's and maybe proof load or something like that. It was used by the fastener engineers to make recommendations to the design engineers (like the suspension guy). I think it was a GM book, not just a Chevrolet book. Now this was back in the early 80's and I was in the fastener lab and only worked there for about 6 months during my "Engineer in Training" time and all the fastener guys I knew are gone.

I did call someone (fastener engineer) out of the GM people finder and he was able to find the info on the one fastener I needed on a drawing in the online system. I think I will try again and see if someone has the old book on their desk. As you know a lot of that stuff just gets thrown away when the computer took over.

My job in the lab was to make up the joint out of the production pieces and run 5 fasteners down using strain gaged bolts while measuring torque. This data was graphed and torques were determined for the individual joints.

Chris

[Howard M.]

Re: bolt/nut/etc callout

Thanks for the input. I imagine we have to guess what bolt/screw goes where when we put these old (C1) cars together.

[Wayne M.]

What about Gr. 8.900 in P&A catalogs ?

Surprised no one has mentioned this source. It's not a comprehensive listing (I can only find a few AIM part #'s for my '65) but it lists the description as you stated, and states the parts group in which it is used (or the unit price if too general for a group), for about 30 bolts (cap screws) for each diameter and thread count.

Is the 122320 the # you are looking for ? If you give its diameter that narrows the search.

Same for machine screws, nuts, washers, etc; about 25 pages in all.

[Howard M.]

Re: What about Gr. 8.900 in P&A catalogs ?

Hi: Thanks for the info
Not familiar with "P&A" catalogs. Only thing I have is the Chassis and Body parts catalog (14A) which does not have a section 8.900. I used the 122320 bolt only as an example of a callout in the assembly instructions that isn't defined. I've taken everything apart and found a wide variety of bolts were used during a previous reassembly. Apparently the body shop grabbed any bolt they could find without regard to style or length. I would like to know the correct type of bolt for its application (front bumper guard to bracket as an example).
I quess at this point, it is easier to buy complete sets of bolts and screws from aftermarket suppliers for the different assembly areas.

[Joe L.]

Re: What about Gr. 8.900 in P&A catalogs ?

Wayne and Howard----

The Group 8.9 "standard parts" section of the P&A Catalogs and the later, stand-alone "Standard Parts Catalogs" (which replaced the 8.9 listings in the regular P&A Catalogs) are a good source for information about fastners. However, it's quite limited. For one thing, most of the PRODUCTION-utilized fastners were never available in SERVICE. So, they won't be shown in any group 8.9 listing.

For another thing, the part numbers changed over time. So, a later edition of the P&A Catalog or Standard Parts Catalog won't necessarily have the fastners that you're interested in contained in it even if they were once available in SERVICE.

As far as headmarkings go, there will be NO information found in any GM parts reference source. Many different manufacturers may have supplied a certain fastner over the years of its availability and use. For instance, there are still some fastners available from GM under the original part numbers as used for C1 Corvettes (not many, but a few). However, if one thinks that these will still have the original headmarkings, one is dreaming. Many of the original fastner manufacturers are long-since out-of-business or have been absorbed into other companies with different names (and, consequently, different headmarkings).