I have a couple of boards that are parts of a table I am assembling, and I wish to know the name of the metal piece of hardware circled in red, below. I would have thought it was called a bolt, but I cannot find anything like it under the name "bolts" at home depot.
EDIT:
Upon closer inspection, the hardware appears to be threaded inside for accepting a machine screw. This may help with identification, and I believe that one or two of the answers below may be already correct. I am reluctant to remove it from the hole because I do not want to risk stripping the wood in the hole.