Originally Posted by Bill Kapaun

What "speed" chain are you trying to break?
I've used a similar tool for up to 9 speed. I don't know if 11 uses smaller pins???
I push the pin in multiple steps.
Push a bit, back off and realign. Repeat.....
It also helps to grease the threads.
I destroyed my 1st one in 2 chains, trying to push the pin all the way in 1 try. I still have the 2nd one I bought, although the threads have worn to "sloppy"
Since upgraded to the larger PARK.