Bolt size for trackbar?

I was out with my buddy the last night wheelin. Everything is going good until i turn onto the road and the steering goes all sort of crazy. I think "wtf is going on", so I pull over to inspect the Jeep and I see my trackbar hanging down. It was late so I just caught a ride with my buddy. I don't exactly know how but the bolt came out and it appears to be the only thing wrong with it.

What is the size of the bolt that I need to get? I am just gonna use this as an excuse to finally buy an adj. trackbar. I just need to get it to my house (about 7-8 miles if that).

Its metric and the stock one uses a 15mm head beyond that good luck same thing happened to me When I was 500miles from home 2 weeks ago.
Does yours have that threaded plate or the nut welded to the axle?

My OEM replacement was a 1/2 x 20 thread pitch and I believe a 3/4" head.