Ronstan RF20312 Series 20 Triple Block with 2-Axis Shackle Head and Becket

The Ronstan RF20312 Series 20 Triple Block with 2-Axis Shackle Head and Becket delivers high-performance efficiency for dinghy and small keelboat sailors who need precise feedback from their control lines. This 20mm triple block features an innovative two-stage bearing system that maintains smooth operation under both moderate and high loads, making it ideal for hand-held lines where sensitivity to wind changes is critical.

Innovative Two-Stage Bearing System:

At the heart of this block is a unique dual-bearing design. Acetal ball bearings provide exceptional efficiency under moderate loads, ensuring smooth operation during normal sailing conditions. As forces increase, a plain acetal bearing running on a stainless steel race takes over, protecting the ball bearings from distortion while maintaining low friction performance. This intelligent system delivers consistent performance across varying load conditions.

Durable Construction:

• UV-stable acetal sheave for long-lasting outdoor performance
• Fiber-reinforced nylon cheeks provide rigidity while minimizing weight
• 316 stainless steel load straps add structural strength
• Low-profile shackle pin head prevents snagging on smaller diameter lines
• 2-axis shackle head allows multi-directional attachment flexibility
• Integrated becket for easy system rigging

Ideal Applications:

• 6:1 purchase systems for backstays
• Boom vang controls
• Outhaul adjustments
• Halyard tuning systems
• Cunningham controls
• Backstay tensioners on dinghies and smaller keelboats

Specifications:

• Sheave diameter: 20mm
• Recommended line size: 1/4" (6mm)
• Shackle pin diameter: 1/8"
• Configuration: Triple sheave with becket
• Attachment: 2-axis shackle head

This lightweight, high-efficiency block is designed to help sailors detect subtle changes in sail trim and wind conditions, providing the tactile feedback needed for optimal boat performance.