The stock bed bolts are not regular Torx heads. They are Torx Plus TP45. You will notice that the regular Torx bits do not fit properly, which is one reason they break while trying to remove the bolts.

That said, I had no luck removing my bed bolts with the proper tool. The bolt heads started to strip out, so I cut them off with a cutoff wheel on a 4 1/2" grinder. I removed one by welding a large nut onto the head and using a powerful impact wrench, but that was more trouble than it was worth.

The stock bolts do indeed form their own threads. Google "Trilobular" for more information.