They're metric, 12 mm, not 1/2".
I believe they are 12 mm x 1.5 thread pitch.
12 mm is available in 1.25 and 1.5 thread pitch, there is also a less common 1.75 thread pitch in 12 mm. I cannot be 100% certain the Pantera is 1.5 thread pitch until I go home this evening, which is still several hours away. Perhaps somebody else can verify before then.
It sucks when your memory isn't as efficient as it once was, I apologize.
cowboy from hell