What is the difference between a round-hole seed bead and a square-hole seed bead? Are the two interchangeable?
The overall size of the bead is the same and aside from the shape of the hole in the bead, a square- and round-hole seed bead are the same. The size of the round hole for an 11/0 seed bead and square hole of an 11/0 seed bead measure the same, 0.64mm or 0.025-inches.
The square hole is shaped differently so it does allow a little more wiggle room for when the hole gets filled with thread and you still want to pass your needle through one more time. Also, square holes are often treated with special coatings and the effect is much more dramatic than the same treatment applied to a round-hole seed bead.
- Tammy Honaman, Author, Jewelry-Making Expert and Educator