High Density Ball Screw SetHand crank SFU screw setHigh precision | high speed | low noise | small friction coefficient, quiet operation and smooth operationThe ball screw determines the durability, stability and life of the machine.1204 screw, the diameter of the screw is 12mm, the lead is 4mm1605 screw, the diameter of the screw is 16mm, the lead is 5mm1610 screw, the diameter of the screw is 16mm, the lead is 10mm2010 screw, the diameter of the screw is 20mm, the lead is 10mm. It means that the distance that the screw rotates one revolution is 10mm, which is equivalent to the pitch.The lead screw is made of bearing steel, with high hardness, high precision and durability.Positive and negative rotation and smooth sliding: It can provide left and right rotating docking, beautiful and high-precision positioning.Dust-proof, lubricated and mute: both ends are sealed with polytetraethylene, which is effectively dust-proof and mute.Note: Do not turn the screw nut out, the steel ball inside will come out of the raceway and can't be re-installed again, you can only ask a professional to assemble it.(Note: Everyone uses different places and installation locations, and they are not equipped with mounting screws. Please understand, thank you for your cooperation!)Package content:Hand wheel 1pcsAluminum nut seat 1pcsScrew rod + matching nut 1setBF support end + BK fixed end 1set