[AT] OT drain plug size

[James Peck]

There are sockets specifically made to grab the rounded off bolt heads.

 I welded a nut once onto the head bolt for a Honda. The pleasant side effect was that the welding heated up the bolt enough it broke loose.

[Ralph in Sask.] I haven't tried it on an oil plug but I had a drain plug on a water pump that no wrench would fit and I just welded an appropriate sized nut onto it. Worked fine.

[Cecil]  My 2017 Grand Caravan oil plug rounded off with a 6 point socket..