1967 drip edge rosette rivet

[Thomas N.]

From my observances, I've only seen Rosettes on AOS bodied cars, and pop rivets on St. Louis bodied cars. Of course I don't have as much exposure to these cars as many of you so you can take my observances with a grain of salt. It would be great to let people know what body manufacturer also, so maybe we can derive some correlation over the model year.

[Tim G.]

Tom, both my early cars with rosette rivets are St. Louis cars. I know 142 is an AO Smith car. This would be an interesting one to track.

[Mark F.]

Were the rosette rivets used to attach the VIN plate the same diameter; grip range; and composition (aluminum ? or stainless ? - I don't know); as the pop rivets seen on some of these drip edge wiring clips ?

As we all know, the VIN plate was attached to the metal Z-Bar...so, was that bar the same thickness (grip range) as the fiberglass surround where the drip edge clip was attached ?

gmpartsgiant.com describes GM 9424862 as follows: Rivet 1/8 X .318 Style 1C
What does "style 1C" mean ? (I tried to find out but had no luck...just kept seeing that "C" probably stands for countersunk)

PS - my K28 (6/28/1967) Body Build Date has a pop rivet. it's loose and even though I know I didn't change it, I can't be sure it's original...

[Gary B.]

Mark,

I asked Google Gemini AI bot what the 1C means and it said:

“In rivet nomenclature, "1C" likely refers to the head style of the rivet. While specific coding systems can vary slightly between manufacturers or industry standards (like AN or MS for aircraft rivets), "C" often designates a countersunk head, meaning the rivet head sits flush with the surface of the material. The "1" preceding it could be a further sub-classification within that style or indicate a specific angle for the countersink, such as 100 degrees. For instance, in some systems, a "C" might specifically refer to a flush head, and the "1" could indicate a standard 100° countersink.”

Gary

[Gary J.]

My ‘67 is a St. Louis built car also.