Series 30 Ball Bearing Block – Single – Loop Top
Features:
- Low friction 2-stage ball bearing system provides consistent performance over the full working load range
- High static and dynamic load capacity
- Light weight
- Versatile head fittings
- Sheaves running on Acetal or Torlon® ball bearings provide high performance & low friction
- Can be fitted with a shackle in either of two planes to allow correct alignment of the block
Applications:
- Primary lead blocks on dinghies and catamarans
- Control lines on larger yachts
Materials:
- U.V. stabilized Acetal sheaves
- Acetal ball bearings
- Impact modified, fiber reinforced and U.V. stabilized Nylon cheeks
- Grade 316 stainless steel load straps and head fittings
Specifications:
Sheave Ø:30mm(1-3/16″)
Max. Rope Ø:8mm(5/16″)
M.W.L.:300kg(660lbs)
B. L.:750kg(1,650lbs)
Weight:28g(1.0oz)

![Ronstan Series 20 Ball Bearing Block - Single - Cheek Rivet Mount [RF20151A]](https://www.yachtseatworks.com/wp-content/uploads/2026/10/ronstan-series-20-ball-bearing-block-single-cheek-rivet-mount-rf20151a.webp)
![Ronstan Series 30 Fiddle Block - Narrow w/Tube Rivot Head [RF186]](https://www.yachtseatworks.com/wp-content/uploads/2026/10/ronstan-series-30-fiddle-block-narrow-w-tube-rivot-head-rf186.webp)
![Ronstan Series 20 ball Bearing Block - Triple - 2-Axis Shackle head [RF20302]](https://www.yachtseatworks.com/wp-content/uploads/2026/10/ronstan-series-20-ball-bearing-block-triple-2-axis-shackle-head-rf20302.webp)
![Ronstan Series 20 Ball Bearing Block - Double - 2-Axis Shackle Head [RF20202]](https://www.yachtseatworks.com/wp-content/uploads/2026/10/ronstan-series-20-ball-bearing-block-double-2-axis-shackle-head-rf20202.webp)
![Ronstan Series 20 Ball Bearing Block - Upright Lead [RF20171]](https://www.yachtseatworks.com/wp-content/uploads/2026/10/ronstan-series-20-ball-bearing-block-upright-lead-rf20171.webp)
![Ronstan Wire Block - Ferrule Top w/Removable Nylontron Sheave - 45mm (1-34/") Sheave Diameter [RF104]](https://www.yachtseatworks.com/wp-content/uploads/2026/10/ronstan-wire-block-ferrule-top-w-removable-nylontron-sheave-45mm-1-34-sheave-dia.webp)
![Ronstan Series 25 T-Track - Composite Slide - Series 40 BB Orbit Block - Stand Up - Suits 9mm(5/16") Rope [RC72536S]](https://www.yachtseatworks.com/wp-content/uploads/2026/10/ronstan-series-25-t-track-composite-slide-series-40-bb-orbit-block-stand-up-suit.webp)
![Ronstan Series 20 Ball Bearing Block - Double - Becket - 2-Axis Shackle Head [RF20212]](https://www.yachtseatworks.com/wp-content/uploads/2026/10/ronstan-series-20-ball-bearing-block-double-becket-2-axis-shackle-head-rf20212.webp)