Shoulder screws

Anyone know where I can get shoulder screws that are legal for vex competition use?

VEX sells them in the Screws Category. Robotmesh also sells it.

This a special size (to fit the square vex holes), so there is not an alternate industrial supplier for these. Also, industrial shoulder screws are precision ground, and this size (3/16") would run about $2 each, so the VEX price is actually a good deal.

Can you get them in any length?

You can but shoulder screws tend to be a bit pricey. Buy them from Vex or be prepared to shell out some dough.