Ungula and ring fracture are due to higher surface hardness.The rational suggestions to settle fracture are put forward.

爪形和环形断裂由表面硬度偏高造成,并提出解决断裂问题的合理化建议。

Ebonite is one kind of special rubber product with high strength, high modulus, high hardness and fine unnotched impact resistance.

硬质橡胶是一种具有高强度、高硬度、高模量以及良好无缺口抗冲击强度的特种橡胶制品。