fastener part numbers

[Robert S.]

Looking at my 1971 AIM, I see that part numbers are given for the various bolts, nut, washers, etc. If I would like to know specifics for a particular fastener, for example, the size of a bolt, is there a document that I can access (old parts book?) that would have that information given the part number?

I'm a fairly new Chevy guy (for older Vettes).

[Jack C.]

Re: fastener part numbers

I believe Richard Fortier can help you. 810-750-1472.

[Jeffrey S.]

Re: fastener part numbers

Robert:
If you can get a hold of an old Parts and Accessories Catalog, the illustrated section very often will have the thread size and length of the fasteners. It does not show the head markings or finish. These may or may not be the exact length used in production.
Jeff

[Robert S.]

Re: fastener part numbers

Thanks for the feedback. I just didn't know what the availability of an old parts book would be. But I will start searching to see what I can find.

What I want to do is look over my car and check to see if what I have is or is not reasonably correct. I realize that bolt head markings would not be provided, but I would like to verify the correct type and style of bolts, washers, and nuts as a start (chassis, interior, and engine).

[Chuck S.]

Re: fastener part numbers

Thanks for the feedback. I just didn't know what the availability of an old parts book would be. But I will start searching to see what I can find.

What I want to do is look over my car and check to see if what I have is or is not reasonably correct. I realize that bolt head markings would not be provided, but I would like to verify the correct type and style of bolts, washers, and nuts as a start (chassis, interior, and engine).

Fastener descriptions for restoration have always been difficult to obtain from text records if an original fastener is missing. In my opinion, attempting to find fastener descriptions is a waste of time unless someone bought a car in boxes, and then I'm thinking the first time restorer is in over his head. If you're missing a fastener on an assembled car, you can examine a similar model year Corvette and duplicate that fastener type and headstamp.

You can pretty much assume that existing fasteners on a car are orignal unless it has been "restored" by someone who scambled the fasteners, or thought it was a good idea to change to all new fasteners. Changing to all new fasteners is NOT a good idea for a judged car. Wholesale fastener replacement, however, is not something past owners most interested in driving the car would have done.

As you restore a car, you become familiar with the headstamps that occur most frequently on the car. You will see a pattern of a few headstamps/manufacturers that were used by GM during that time period. You will realize that any given fastener application may have multiple headstamps on the same car. For example, one side of a 70 Corvette may have bumper bracket bolts with an M headstamp, and the same bumper bracket bolts on the other side have an A headstamp. In this case, there is no ONE correct headstamp...either headstamp is correct, and can be used interchangeably.

A 70 Corvette may have A, M, RBW, C, anchor, SC, RBS, TR, L5, WB and other fastener headstamps to identify the original manufacturer. In addition to the manufacturer's ID, there will be a variety of other additional industry standard marks to identify the strength and type of fasteners. Over the years, maintenance may have changed the fasteners around (engine work for example), but each application should be the same type fastener. You will not see ALL the above headstamps in all sizes and applications; during a specific time period, certain sizes and types of fasteners may have been ordered only from certain manufacturers.

Occasionally, you will find a headstamp that doesn't fit the pattern, and that may be a Home Depot replacement made by someone without knowledge. You should check it out...I don't think HD has anything stronger than Grade 5. If you run into a headstamp that doesn't fit your car's "pattern", ask about it here.

[Mike E.]

Re: fastener part numbers

Looking at my 1971 AIM, I see that part numbers are given for the various bolts, nut, washers, etc. If I would like to know specifics for a particular fastener, for example, the size of a bolt, is there a document that I can access (old parts book?) that would have that information given the part number?

I'm a fairly new Chevy guy (for older Vettes).

You might retry your post at some time in the future with a bit of a different bent. You might try to find someone (and there are a number of us around) who are anal-retentive enough to have logged in the size and headmarking of every bolt and fastener on their car. That generally is done when someone does a body-off, has all their hardware replated, and wants to keep records of what went where. There has to be someone with a 71 who has done that. That won't mean that every fastener on yours will be identical with theirs. but it will give you an outstanding baseline from which to begin.
I pretty much have that for 62 and for 67, but not for a 71. If you do find such results, I'd love to have a copy.

[Lynn H.]

Re: fastener part numbers

I happen to be one of the anal retentive individuals mentioned above. I currently have five cars and have disassembled and parted out about 20 over the years. Because I am possibly nuts (if you ask some that know me) or just do not have anything better to do, I have about 200 pages of handwritten notes on fasteners that I have removed over the years. I keep track of head markings, style of screw or bolt, size, length of bolt, length of thread, and any other idenifying features I deem to be unusual or of significance. My line is that it is for the book that I am going to write someday, but as is the case most times someday never arrives. I would say that the majority of the cars I have taken these notes from were of the 68-72 vintage. I would be more than happy to check on any individual fasteners that you would have questions on, that are in my notes. I would say that I could scan them and email, but between my handwriting, and my system (that probably only I would understand), that might prove to be very confusing. You can email me directly with any questions youmight have at corvettelynn@comcast.net.

[Robert S.]

Re: fastener part numbers


My intention at this point is not to do a complete body-off as the car is in fair condition, but it does need a lot of detail work. But I am quite picky about fasteners as I feel it is one of those details that can really improve a car.

[Robert S.]

Re: fastener part numbers

Gilbert, I appreciate your offer to share what you have put together. You must have a goldmine of information on these cars.

[Gary C.]

Re: fastener part numbers

Robert, early P&A books have a standard fastener section in group 8.900 Late 60's or early 70's the standard fastener section became a stand alone book. As Joe, Duke and many others will tell you the production line fastener numbers in the AIM generally are not the same as what's in the standard fastener section. There is a GM Engineering standard fastener reference with thousands of pages that I've been told about, have never seen, which would probably include most of the AIM fastener numbers and their specifics in it. Example about standard fastener section 8.900 in the P&A - there are about 6 part numbers that are the same as in the '56-7 AIM. Best source is other anal Members who have restored and logged all of their bolt head and fastener information. Unfortunately, there is no single source - but would be a good book to publish. Best, Gary....

[Lynn H.]

Re: fastener part numbers

I would love to think the information I have kept track of over the years would one day help promote the hobby.
Maybe "someday" will get here and I will write that book.......

[Robert S.]

Re: fastener part numbers

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[Jack H.]

Re: fastener part numbers

The Engineering Standards book that Gary mentioned is the best reference, but even that will NOT get you the information you seek (what's factory correct/original for my car?). Why?

Well, on fasteners and other purchased parts, GM typically had more than one qualified supplier. The head marks on their parts were specific to the supplier. These were typically inter-mixed on the assy line(s) making it a matter of random draw as to what came out of the parts bin for your car the day(s) it went down various assy lines...

Looking at other restored and original cars is only going to tell you what THEY decided was right/correct for their car. Plus, there were cases where this that fastener was substituted to keep the line up and running...

[Robert S.]

Re: fastener part numbers

I realize that parts that happened to be available were used regardless of what part number was specified. But what I would like to do is at least flag any fasteners that appear inconsistent and obviously incorrect. As was suggested, I could then see what other similar cars have for these and replace as I feel necessary. So I'm looking forward to looking attending as many car shows as I can.

From everyone's comments, I'm beginning to see that this fastener topic is quite involved. More than my simple mind expected.

[Ned T.]

Re: fastener part numbers

Im glad to see there is no easy answer to this fastener question. I have been struggling with this problem for quite a while. I have asked members here for different head markings on individual bolts and got great responses. Now that I see different fasteners could have been used on different cars and even different sides of the car I dont feel so bad. Ive tried to find correct head markings before plating a bolt, even though my intention was to use all grade 8 bolts before I got this deep into it. I have a complete stock of grade 5 and grade 8 coarse and fine which I thought was going to be helpful. It has been a challenge. My car has been apart before to throw a little more cunfusion into the mix. So Ill get all I can correct and wing it for the rest.