Stupid Question - What does Sway Bar Rubber Sleeve/Clamp do?

[68camaroz28]

George's picture is quite interesting. Both our 68 sway bar and brackets were painted black with the brackets seemingly dipped as many others due to small runs.

[Hans L]

Interesting.  I painted the sway bar brackets a semi-gloss black, same color as the sway bar itself which appears to be correct now.   

But the sleeve clamps had light surface rust so I assumed they were natural finish.  I don't recollect seeing any paint remanents.  Easily could have been phosphated as that does not last long.   Also, from the picture posted, the insides appear dark (phosphate).   No chance it could just be the black bushing rubber rubbing off on the inside?   Does it appear the outer surfaces were phospated as well?  I see light surface rust and natural metal, which is why I'm asking.   

No expert, so looking for advice as well.

[NoYenko]

The "U" clamps holding the sway bar to the subframe on my car were definitely dip painted black. But the bushing sleeve clamp was rusted on the outside without paint.
I took it to a wire wheel before blasting it to see if it was silver zinc or black on the outside. It sure looked like it was dark phosphate. The zinc or phosphate blasts off very quick as is thin. A dipped painted part is harder to remove the paint. There were 2 rubber marks from the seam in the bushings that were harder to remove than the phosphate. The inside of the clamp had the rough feel to it like phosphate.  George.

[randfr]

any ideas on where to buy the rubber insulators that go into the metal clamp?  or a decent substitution?

an online place that sells the metal clamp suggests "You will need to reuse your old rubber insulators or cut rubber strips to insulate the bracket."

[Prackman]

"any ideas on where to buy the rubber insulators that go into the metal clamp?  or a decent substitution?"

Any updates on a source for the rubber components?