I use a T track router bit that is meant to create a path for 1/4" hex bolts in wood. Its a really nice feature to have for DIY projects, but occasionally, the hex bolt rotates and causes friction when moving. I know that some people use toilet bolts (Although, I'm not sure where they get them, or if there is a significant price difference, or their TPI for that matter) What are the differences between toilet bolts and how they interact in a T track? Do toilet bolts typically slide better? Are they harder to get in different sizes? What are some differences between them? Are there other kinds of bolts usually used in T tracks?
They are available at most any hardware or home improvement store. Since the head is oblong, it cannot twist inside a T-Track. Other than that, they are really no different that any other bolts. Woodworking stores offer specific TTrack bolts which are pretty much the same thing.
You can also try carriage bolts. Generally, you shouldn't have problems with regular hex bolts unless you are really over tightening them, or they are undersized.