Description
Series 40 Ball Bearing Block – Single Upright Lead
Lead blocks are a low profile solution for leading halyards or other rig sail controls back to cleats or jammers. Precision molded Acetal sheaves running on Acetal or Torlon ball bearings provide high performance & low friction. The 2-stage ball bearing system provides consistent performance over the full load range.
Applications:
- Typically used for halyards at the mast base.
Materials:
- Acetal ball bearings
- UV stabilized Acetal sheave
- Grade 316 stainless steel load housing

![Ronstan Series 55 Ratchet Mount Orbit Block – Fiddle Becket Swivel [RF56510]](https://www.apartship.com/wp-content/uploads/2025/4/1745803850/ronstan-series-55-ratchet-mount-orbit-block-fiddle-becket-swivel-rf56510-1745803854.webp)
![Ronstan Series 40 All Purpose Block – Double Block – Full Swivel Head [RF41200]](https://www.apartship.com/wp-content/uploads/2025/4/1745803591/ronstan-series-40-all-purpose-block-double-block-full-swivel-head-rf41200-1745803595.webp)
![Barton Marine Size 0 20mm Plain Bearing Pulley Block Cheek [N00160]](https://www.apartship.com/wp-content/uploads/2025/4/1745803739/barton-marine-size-0-20mm-plain-bearing-pulley-block-cheek-n00160-1745803743.webp)
![Ronstan Series 50 All Purpose Block – Triple [RF51300]](https://www.apartship.com/wp-content/uploads/2025/4/1745803850/ronstan-series-50-all-purpose-block-triple-rf51300-1745803854.webp)