Selecting the appropriate gripping mechanism is critical to maintaining the performance and surface integrity of your linear motion system.
A. Set-Screw Collars (Economy Point-Contact)
Mechanism: A solid ring utilizes a single threaded set screw (grub screw) that exerts point-contact pressure directly onto the shaft.
Technical Constraint: On hardened linear shafts (HRC 60), the set screw often fails to penetrate the surface, leading to slippage under axial impact. If penetration occurs, it creates a raised burr or "crater." Sliding a linear bearing over such defects will gouge internal seals and fatally damage the recirculating ball circuits.
Ideal Use: Low-impact, static applications where the collar will not be repositioned.
B. Single-Split Clamping Collars (The Industrial Standard)
Mechanism: Features a radial slit and a high-tensile cap screw. Tightening the screw induces circumferential friction clamping, providing 360 degrees of uniform pressure.
Advantages: This design delivers superior holding power compared to set-screw models. Because it relies on friction rather than surface penetration, it is entirely non-marring, preserving the precision-ground finish of the linear shaft.
Ideal Use: High-dynamic automation, heavy-duty impact stops, and systems requiring frequent positional adjustment.
C. Double-Split / Two-Piece Collars (Maximum Serviceability)
Mechanism: The collar is split into two independent halves, secured by two opposing bolts.
Advantages: It provides the same non-marring, high-torque clamping as the single-split design with the added benefit of radial installation. It can be installed or removed anywhere on a captive shaft without disassembling the machine or removing end supports.
Ideal Use: Maintenance-heavy environments, retrofitting existing machinery, and assemblies with complex, non-removable shafts.