Description
Series 20 Ball Bearing Block – Single
Features:
- Low friction
- High static and dynamic load capacity
- Lightweight
- Precision molded Acetal sheaves running on stainless steel or Torlon® ball bearings provide high performance & low friction
Applications:
- Dinghy control lines
- Dinghy Vangs
- Cunninghams
- Traveller controls
Materials:
- U.V. Stabilized Acetal sheaves
- Stainless steel ball bearings
- Grade 316 stainless steel load strap and head fitting
- Impact and UV resistant, fiber reinforced Nylon cheeks
Specifications:
Sheave Ø:20mm(3/4″)
Max. Rope Ø:6mm(1/4″)
Pin Ø: 3mm(1/8″)
M.W.L.:250kg(550lbs)
B. L.:550kg(1,210lbs)
Weight:20g(0.7oz)


![Ronstan Series 50 All Purpose Block - Double [RF51200]](https://www.bestmarinebattery.com/wp-content/uploads/2026/08/ronstan-series-50-all-purpose-block-double-rf51200.webp)

![Ronstan Series 15 Ball Bearing Utility Block - Pivoting Lead Block [RF15174]](https://www.bestmarinebattery.com/wp-content/uploads/2026/08/ronstan-series-15-ball-bearing-utility-block-pivoting-lead-block-rf15174.webp)
![Ronstan Series 40 Orbit BB Quin Block w/Swivel Shackle [RF48500]](https://www.bestmarinebattery.com/wp-content/uploads/2026/08/ronstan-series-40-orbit-bb-quin-block-w-swivel-shackle-rf48500.webp)



