Xi'an Tydrillbits Co.,Ltd is one of the most famous China tool-holders manufacturers,Website:://.tydrillbits.com, welcome to wholesale cheap tool-holders from our factory.Material：40CrMnMo（4140），42CrMnMo（4240）Specification：S100,S160,S200,U170......In addition to common specifications, our products can be made according to your drawings or samples.