If you have a fixed handled hammer and the head is a little loose, this is the solution.  Apply a few drops to the top of the hammer handle and after an hour or so, the handle will be tight.  For particularly loose handles, multiple applications and waiting overnight may be necessary.  This is not a glue.  It is a mixture of dipropylene glycol and water.  

We repackage from the manufacturer's bottle and sell in a 1/2 oz bottle which is enough for 5-6 applications.

In case you are wondering about dipropylene glycol, you can learn more about it here.