... : Ball Dia. n: Number of circuits K: Stiffness (kgf/μm)Ca: Basic Dynamix Rating Load (kgf) Coa: Basic Static Rating Load ... on many models.specification list (SFI and DFI): 1204-3,1605-4,1610-3,2005-4,205T-4,2505-4,3205 ... ,6310-4,8010-4specification list (SFU and DFU) 1204-3,1605-4,1610-3,2005-4,2505-4,2510-4,3205 ... we can help you Keep your business up and running. 1605 Ball Screw