Best hardness ratio：Effectively prevent serious damage to the piston or tool due to imperfect proportions.

High wear resistance：To help customers reduce operating costs.The wear resistance of all series has reached the international advanced level.

Best fatigue performance:Help customers improve productivity and effectively prevent unplanned downtime. Yulingingli not only realized deep shell hardening with technical level, but also kept the core of drill rod soft, which is the embodiment of technical level.