need to identify a Part from a Sigma 75-300

[Jules0770]

HIya
Thankyou for accepting me on the site.
I was tightening the bracket screw on a 75-300 which is now done and its nice and secure.
Sadly i cant put it back together as a part came out and no one can identify it?

Maybe some one here can help.
Its the brass horse shoe looking piece in the photo.

Thank you for looking.

[David Kilpatrick]

Jules, welcome to the forums, but you did not post a photo.

David

[Jules0770]

Trying again to post so fingers crossed it will work, photo now attached
Thanks David

[David Kilpatrick]

Sadly, I have no idea - I've never had one of those fall out of a lens. It looks like a circlip so if it is loose, something else will not be properly retained.

David

[UrsaMajor]

I have no idea what that part is, since I have no knowledge of the lens design details.

However, I have seen similar parts used in other applications as shims on a screw to adjust a clearance or dimension. IMO, such a use is not good design as the shim might drop out if the screw loosens. A precision washer would be much better in such an application, but a horseshoe shim does save assembly time during manufacture, since it is not necessary to completely remove the screw to make a change.

As I said above, I really do not know the purpose of this part, but if I were to be forced to guess I would vote for its usage as a shim.

With best wishes,
- Tom -