... allow the central hole of the supporting parts. The top is mainly composed of a thimble, a clamping device ... center hole or pipe material, on the other end can be top end is a spherical or conical parts, thimble by ... the fixed pin pin or, to achieve the top two. Top can also be used for the work of the ... concentric precision.5. Sealing ring at the fron end is dust proof and water proof,can avoid coolant ...