Borromean rings consists of three rings, linked so they can't be pulled apart. But no individual ring links with any other ring. Removing any one ring results in unlinked rings. Starting out you saw out the shape. I used a 1 3/4 inch square block. the ring shapes are 1/4 inch. The next step is to carve out the little squares. Then use a small drill and drill the inside corners in all directions. Start rounding the outside rings. Then use a small knife, gouge to separate the rings and finish rounding.