Stability: Iron kernel is more stable, not easy to crack, which is very important for nuclear carving works. While the oil core, although the oil is larger, the color of the pulp faster, but the stability is relatively poor, easy to crack and other problems.

Density: and the hard texture of the iron core, carving is relatively more difficult, requiring more exquisite skills. And the texture of the oil core is relatively soft, carving is relatively less difficult.