Description
Harken 57mm Black Magic Air Low-Load Double Block are a top favourite of Big Boat performance racers and cruisers. These lightweight, free-running, powerful performers are used for sail controls that see lots of action: mainsheet, runner, halyard, and spinnaker systems. A centre cage keeps Torlon® roller bearings separated and parallel to reduce friction. Shackle blocks lock in two directions or swivel to keep line from twisting.
Low-load blocks have red isolators. They use Torlon® rollers and 316 stainless steel shackles. Standard blocks have 17-4 PH stainless head posts.
Torlon is a registered trademark of Solvay Advanced Polymers L.L.C.
| Sku | Name | Sheave Ø mm (in) | Length mm (in) | Weight g (oz) | Maximum line Ø mm (in) | Maximum working load kg (lb) | Breaking load kg (lb) | Shackle pin Ø mm (in) |
|---|---|---|---|---|---|---|---|---|
| 3228 | 57 mm Black Magic Air Aluminium Low-Load Double Block — Swivel | 57 (2 1/4) | 132 (5 3/16) | 342 (12.05) | 12 (7/16) | 1250 (2755) | 2500 (5510) | 8 (5/16) |
