Is this the through-bolt that passes through the top of the Elevation Bracket and Mast Clamp assembly and secures the dish assembly through the hole in the motor tube?
You could find replacement hardware at a local hardware store. Usually the through-bolt can be replaced with a 1/4" x 2 1/2" carriage bolt. Purchase a split lock washer and nut and you should be set.
If you want an original bolt package, please give our support department a call and let us know if it is a full threaded carriage bolt or a crown carriage bolt (threads only on the end of the carriage bolt).
We have changed all GEOSATpro 90cm hardware over to SAE, but we should have some of the old metric hardware screw packs in the bins.
I twisted off the heads of many a cheap bolt on my old no-name 30" trying to make sure they were tight. On my GeoSatPro 36", I was more careful -- or at least I thought I was! I didn't twist any heads off, but one of the bolts practically exploded -- it actually flew out of the hole, which is impressive because it was the long one through the motor tube! This was just with a cheap handheld ratchet that probably isn't even 6" long. (Some of the no-name ones, however, were with even less force than that.)
Men are well known for over-tightening bolts. Believe it or not, I read an article this morning on the Beretta Nano 9mm pistol and it said this very thing -- men over-tighten and break things -- it's not just satellite guys. Heck, my first car I snapped a bolt while replacing a water pump. From that I learned it is why they invented the "Easy Out", but if you're a confirmed bolt snapper, the Easy Out is the most mis-named product imaginable. It ain't easy! It's easier to break than the bolt you just left in your engine block.
Now don't get torqued off at me, it's just our nature. Tighter, tighter, just a little tighter, c'mon, *&%^$# !!
Some men learn from this, some will never learn. In the latter case, ask a lady to tighten things.