What is this piece called?

[Matt89]

Can someone tell me what this is? Its a hollow bolt with external threads with an insert on the side that can be tightened with a hex key/Allen wrench. Thanks!

 

[Lee Celtic]

looks like a spindle adapter.. push it onto a spindle of say a bench grinder and tighten the grub screw then you have a thread you can put a stone, pully wheel or sprocket on add a nut and tighten up .. at the top of the thread you can see two flats to lock the thing when tightening the nut..

I think..lol

 

[gdocktor3]

Ya my first thoughts were arbor or spindle adapter as well.

 

[Matt89]

Thanks!