Identify that rivet!

[Matt]

Alright everyone, I've never seen a rivet like this before & have called a few rivet specialty places & they were not able to identify it either. I apologize for the picture quality; it's blown up a touch to show the detail. The actual size of the rivet head is about 5/16". The head appears to have 2 sections (the main one is a little worn on this one) and then on the inside there appears to be a very small square drive down inside? Anyone recognize what it is? It almost looks like it might be removable?? I cant find any square drives that fit it, it's quite small. Take a look...

 

[Steve26]

Looks like a Cherry Max aircraft rivet to me. Is there a thin locking ring around the stem (broken part)?

 

[Jeremy Tygrett]

Im gonna agree with that as well. Cherry Aerospace

 

[cal]

looks like CR3213-5 cherrymax.

- take a sharp punch, punch out the center stem, or at least get it started
- take a #20 drill, drill out the locking collar, but dont drill too far down
- take sharp punch and drive out the center stem
- using same drill, drill down until level with surrounding material
- use a 5/32 punch to snap of head
- punch out remaining rivet shank with 5/32 punch
- follow these steps and you wont go wrong
- if the base material is really light, grind the top of the rivet down with a 90 degree grinder, use a fine grit disc. then gently punch out the center stem
cal

 

[Matt]

What's with the square drive in the center then? I was mainly hoping it was removable, if not I'm probably not going to take them out as they're going into the frame & don't want to have a bunch of shavings & ends stuck in there forever.

I'll send a message to them as well. Thank you all!

 

[Bill Musarra]

Mat,
First off you will never see them if you did, and they won't hurt anything. Second if you are worried about hearing them rattle around, You might need a bigger engine.:huh::evil:

Bill

 

[cal]

the center stem is the steel "driving anvil", thats what makes a cherrymax a "solid" blind rivet with great strength properties vs standard pop rivets

also, a foot note to grinding the head off the rivet before knocking out the center stem. you need to grind down far enough so a much lighter hit with the pin punch is required to dislodge the locking collar. use the grind method on light skin areas.
you can go direct to the pin punch on areas of greather thickness.

 

[Matt]

I'm pretty sure with the 408 w/ stacks & snakes that won't be an issue. My problem is if I know it's there I'll "hear" it regardless :laugh:

I should be alright without removing them though. Thanks for the tips in case I do!