BSF Ballnut: C7 Rolled and C3,C5 Ground Ballscrew are available. The model for BSF series Ballscrew included: 1204 ,1605 ,1610 ,2005 , 2010 ,2505 ,2510 ,3205 ,3210 FBT Ballscrew Features: 1)High Reliability 2)High Precision 3)Smooth Movement 4)High Axial Stiffness 5)OEM/ODM Production.