Remove a rounded out allen head screw

[Too Hot]

Use a flat metal punch and a hammer. Make a slot and then beat in the lefty loosey direction to loosen it.

 

[Jethro]

If that's a Vessel Impact driver those are JIS not Philips bits. It's probably not likely a pic with that driver and Torx bits will be found. I think the Vessel also uses slightly different size bits than the more common 1/4" drive bits.

Oookay Philips looking J.I.S.

 

[motornut]

I've found Harbor Frt. 'edged tools' to be iffy - sometimes the heat treating is good, sometimes not. Bottom line, I will not waste my money on HF drills, chisels, etc. If you want to use a reverse twist drill bit, get a good brand.. Ez-outs in the smaller sizes (what you will need for that bolt) are fragile and break more often than they work. Larger sizes are more robust, but won't help you. Whatever method you use, try the least destructive first, so that you can try something else.

IIRC, the socket head is recessed in the handlebar, so slotting it for a screw driver will be v. difficult w/o cutting into the handlebar itself (unless you have a dental drill rig). I'd try the torx bit or a ground down allen wrench first, then progress to drilling the head off, removing the handlebars over the stub and then either pliers or vise grips on the stub.

I too have had problems with Harbor freight, most of the time they are one use tools- if that. I have bought the kits such as adapters to different drives. If I use one then it is a short trot to the snap-on truck to replace it with a good one