Specifications: Brand: MssoommManufacturing Process: Rolled ThreadPrecision: C7 Grade, C5 (Grinding grade) is also available, please message usMaterial: GCr15 steelModel: DFU2505This item includes:1pcs Ball Screw DFU2505 RM2505 25mm Length 20.47 inch / 520mm (No End Machining) 1pcs Double Ballscrew NutLead Time: 7-10 Business Days except for for Chinese National Day holiday and Spring FestivalCustomizable Processing and Technical Support:1. We can provide any length that you want, and please let us know what lengths are suitable for you.2. If you need end machining according to your drawings, please tell us before order.3. As a professional seller, we can provide complete information of the products.（Contains CAD drawings and 3D modeling files）Please contact us. 4. All products are provided lifetime technical support.Introduction and Application: Double ball nut designs produce preload in one of two ways: through tension between two single nuts, or through an offset in the lead of a single nut.1. The first method uses a spring or a spacer to create tension between two nuts that are mechanically coupled.During machining of the ball nut raceways, an offset is created in the lead, approximately halfway down the length of the nut body. This lead offset creates preload within the ball nut.Because there are no spacers or springs required, the lead offset method is more compact than a double nut design, but it reduces load capacity. With greater complexity and higher cost, double nut designs are typically used when high preload (7 percent or greater) is required.