Mechanical Part Identification

[bostonman]

I have a few of these parts (see attached) and don't know what they are called.

When turning the threads, the collars expand. I looked on McMaster Carr and thought it was a shaft collar, however, from what I can tell, those tighten on a shaft.

[JohnnyMalaria]

This?

https://www.nriparts.com/products/trantorque-6202240/89647?item_id=289646

[bostonman]

Yes, that's it. I can't believe you found it that quickly.

The website you provided doesn't give any description. Knowing what it's called, I looked on McMaster Carr again because they usually have good information and their Trantorque states it tightens on the shaft too. This one doesn't look like it tightens (I don't have a shaft that fits this to test it), just expands.

[JohnnyMalaria]

I used Bing's Visual Search. I pasted the link to your image, cropped to just the part and up popped the result

[bostonman]

Wow, I just learned two things.

I didn't realize Bing (which I never use) has a visual search.