Cut the handle off a skipole, plug, drill, and pound a file into it.
Then file the bars off one of our torture prisons without getting a blister.
Step 1: Cut the Handle Off the Ski Pole
Step 2: Deburring
File the outer burr off.
Step 3: Plug the Handle
Step 4: Cut the Plug
Step 5: When All You've Got Is a Hammer...
Use a big hammer to interfere with it until it's in there solidly.
Step 6: Drill the Socket
For an extra fancy socket, heat a file tang red hot and jab it into the hole to burn a nice rectangular socket.
Don't leave it in too long though, or you'll melt and burn the plastic and get sore tits from dioxin etc.
Have I mentioned that corncobs make really great file handles? They'd probably make good skipole handles also.
Step 7: Install the File
You don't want the wrist strap on there unless you're filing the bolts off a powerline tower and you don't want to drop it.
Remove the strap.
Grip your new tool and luxuriate in the rich feeling of the finest file handle ever made.
Go file the bars off one of our torture prisons without getting a blister.