Ronstan Series 40 Ball Bearing Orbit Block™ - Single - Becket - Swivel Head

The Ronstan Series 40 Ball Bearing Orbit Block – Single – Becket – Swivel Head is a precision pulley system engineered for applications requiring smooth, low-friction load transfer and directional changes in mechanical linkages and cable runs. Originally designed for marine rigging environments, this ball bearing block has proven invaluable in automotive fabrication, winch installations, and engine compartment recovery systems where reliability and durability matter most. Whether you're building a custom engine hoist, fabricating a cable-driven auxiliary system, or installing a recovery point on your vehicle, this compact yet robust block delivers the controlled mechanical advantage and rotation you need without binding or excessive wear.

At the heart of this design is a single ball bearing orbit mechanism housed in a lightweight aluminum body, allowing the swivel head to rotate freely while maintaining structural integrity under load. The becket attachment point accommodates standard rigging hardware and fasteners, making integration into existing bracket systems straightforward. The swivel head design eliminates chafe and rolling resistance on lines or cables, reducing operational friction that would otherwise accelerate wear on both the block and the load-bearing rope or strap. With a total weight of just 0.1 pounds and compact dimensions of 2 x 1 x 5 inches, it fits tight engine bays and custom chassis builds without compromising accessibility or adding unnecessary bulk.

Mechanics and fabricators rely on this Ronstan block for winch rope redirection, engine lift rigging, and auxiliary drive systems where smooth articulation extends cable life and ensures predictable load distribution. Its marine-grade construction ensures corrosion resistance in high-moisture or salt-air environments, while the ball bearing orbit design resists jamming even in dusty engine compartments or off-road recovery scenarios. Installation is universal—simply mount via the becket using Grade 8 bolts or equivalent fasteners to any structural point, then thread your cable or strap through the swivel head. Compatible with synthetic rope, wire cable, and reinforced webbing, this single block serves as a modular building block for complex rigging systems on everything from custom trucks to performance engines.