Schaefer Single Ball Bearing Block

The Schaefer Single Ball Bearing Block is purpose-built for sailors and boaters who demand smooth, efficient rigging performance under load. Whether you're managing halyards, sheets, or control lines aboard a cruising sailboat or racing keelboat, this compact block delivers the low-friction operation essential for responsive handling and reduced crew fatigue. The single-sheave design makes it ideal for applications where space is tight but mechanical advantage and reliability cannot be compromised.

At the heart of this block sits a Delrin™ ball bearing sheave that rotates freely with minimal resistance, allowing lines to run smoothly even under sustained tension. The aluminum cheeks provide a rigid, lightweight structure that resists corrosion in salt and freshwater environments, while the swivel head design—lockable to prevent unwanted twist—offers flexibility in mounting and line routing. The compact footprint of just 3 × 1 × 5 inches makes integration into existing rigging systems straightforward, and the 0.35-pound weight means virtually no impact on performance or weight distribution aloft.

Cruising sailors, racing crews, and commercial operators all benefit from the reliability and smooth operation this block delivers. Install it in your main or jib sheet system, use it as a controlling block for boom vang or preventer, or incorporate it into deck-level systems where line efficiency directly impacts crew comfort and boat speed. The lockable swivel head ensures the block stays oriented correctly under varying loads, eliminating maintenance headaches and premature wear. Schaefer Marine's proven track record of supplying professional-grade hardware makes this block a trusted choice for vessels of all sizes.