High Precision Miniature Ball Screw (SFK Series) Bearing: TB & TNK Ball crew We are the general agent of Tai Wan TBI ball screw in China. We could supply accurancy Grade C5-C7, preload code: P0-P5 ball screw to our costomers. We also professionally produce ball screw nut and ground ball screw. Ball screw nut is well fited With Tai Wan TBI Ball screw. Both quality and price are good! 1. Accurany Grade: C3-C5(Ground ), Preload code: P0-P5 2.