Ronstan RF40200 Series 40 Ball Bearing Block Double Swivel Head

The Ronstan Series 40 Ball Bearing Block is a high-performance double block with swivel head designed for sailing applications on small to medium vessels. Featuring a sophisticated 2-stage ball bearing system with Acetal or Torlon® bearings, this block delivers exceptional low-friction performance across the full load range.

Key Features:

• Low-friction Acetal or Torlon® ball bearing system for smooth operation
• Swivel shackle head provides full 360° rotation for versatile rigging configurations
• Lightweight construction reduces overall rigging weight
• Cheek cut-outs allow easy access for bearing inspection and maintenance
• 2-stage bearing system ensures consistent performance under varying loads

Ideal Applications:

• Mainsheet systems
• Halyard controls
• Boom vang systems
• Spinnaker control lines

This block is well-suited for off-the-beach catamarans, one-design racing classes, and sportsboats up to 8 meters (26 feet). The double sheave configuration provides mechanical advantage for control line applications while the swivel head eliminates line twist and allows unrestricted block orientation.