Todd,
What do you have, the Magrail or Magrail TL?
The 1/4, 3/8, 1/2, 3/4 and 1' pegs are the same on the Magrail and the Magrail TL.
The threaded studs are different. The Magrail threaded stud is square.
The Magrail TL threaded stud is rectangle and will not work on the original Magrail.