This linear motion shafts are made of bearing steel, which has a good durability and high hardness to ensure a l lasting performance. WIDELY USED: This guide rod is for linear motion, automatic machinery, injection machine, etc. The linear rod is made of bearing steel, the is smooth and flat, it is not easy to and corrode, and it is . We strive to provide you with the highest quality product and the best customer experience, if you're not entirely satisfied, please just feel to us at any time. We strive to provide you with the highest quality product and the best customer experience, if you're not entirely satisfied, please just feel to us at any time.