saarinen stool retaining nut  

by looking at the photo,...
by looking at the photo, it looks like i would need a nylon spacer/washer and a retaining C-clip?
does anyone know the size?
thanks,
fb

McMaster-Carr is a good source for
hardware bits like those. You'd need to make careful measurements yourself, though.
Look for "plastic flanged sleeve bearings" and "external retaining rings" on their extensive site. They are friendly to small orders.
http://www.mcmaster.com/#

MIght as well
get the plier-like tool for installing or removing that clip, too -- practically impossible to do without . . . ?

Full-face protective gear is recommended!
"You'll put your eye out, kid."

thanks guy for the tips
goggle and snap/retaining ring pliers will be used...

I'm cheap --
I just put a paper bag over my head and whang away. You're bound to hit the nail on the head sooner or later . . .
(Actually, my large-lens polycarbonate glasses double nicely as eye protection. As for the rest of my face, any damage would probably result in an improvement !)

My poor attempt at humor.
My best advice regarding springy retainer rings is to buy extras to replace the ones that launch themselves into low Earth orbit. Safety glasses are probably a good idea, too.

since now the retaining ring is not on
i figure perhaps it is a good opportunity to re-grease the internal swivel mechanism. has anyone done that before and can shed some light on tips and do's and don't's?
do i need to completely pull the shaft/spindle out of the base?
when i pull up the seat along with the shaft/spindle a little bit from the base, i don't see any rubber bushing at the contact point between the seat bottom and the top of the base. is it normal? wouldn't the metal grind each other when the seat is swiveling?
i searched everything but couldn't find any photos of the stool after it's been taken apart. it would be great to be able to see how the internal parts are supposed to work with each other.
thanks,
fb

Ah --
good one, then, tk. Don't get me started on masks and ear plugs !
No, I wouldn't expect a rubber washer at the bearing point. Perhaps a nylon or teflon one ? Steel on steel wears very well, actually, but a plastic bushing eliminates noise and permits a bearing surface of softer metal, like aluminum.
If you can't determine the size of spring clip you need, you can cut some trial U-shaped pieces of paper until you get one that fits neatly onto the groove. Poor man's caliper . . . ?

i found this video and http://www.youtube.com/watch?v=6B3X58vZSK0
at 00:23 you can see a black nylon bushing/washer on the shaft. i suppose that's the area where the seat and the base contact with regards to the swivel bearing mechanism?
i also notice that the shaft has grease on it, does anyone know what type of grease should be used for lubrication?
thanks SDR on the tip to measure for the clip.
thanks,
fb

Bicycle shops
have little tubes of synthetic grease safe for use on aluminum alloys.
I don't understand why the shaft won't simply pull out of your base. Does it stop with a sudden thunk, or does it seem to bind gradually?
It seems like you've got a good conversation going with the producer of the YT clip. Maybe he can help.

What I see
at 00:23 could be a roller or needle bearing. We see the exposed rollers in their black-colored cage. The outer ring of the bearing would be found inside the top of the external seat post (the white component, which the operator has removed). This bearing would take the eccentric (side) loads imposed by the moving sitter. The thrust bearing surface(s) -- taking the vertical load -- would be found elsewhere. A quite thorough solution to the engineering problems ?
http://tinyurl.com/7wt2ow4

I have had
the misfortune of redoing a set of these chairs. Depending on the generation, there are simple nylon sleeve bushings. After I got them apart and sent a pic of the pieces to Knoll, they set me up with new ones. The bushings get squished over time, causing the rocking. I would not wish this job on anyone. While conceptually simple, they were unwilling to come apart and go back together beyond any reason or logic. I had to beat them apart. And they did not give up the first, second or third time. It was like trying to start a lawnmower. I got worn out, rested, and had another go. I am decidedly mechanically inclined, but these were beyond comprehension. They did not go back together much easier. For grease I used heavy lithium grease. Good luck.

Oh,yeah
The worry about cracking the seats while pounding and prying was nerve wracking.