Ronstan Block Orbit 40mm Bullet Single with Link

$34.95/ EACH

Code: 21-45101

This Series 40 block is lightweight and has the highest working load in its class. The orbital ball-bearing arrangement gives the largest possible bearing race diameter, maximizing load performance.

To gain peak performance, Ronstan engineered out the heavy steel load straps, head post, shackle, full-length fasteners, and cleating accessories. Through extensive research and development, virtually all metal components have been replaced with high-tech polymers and fiber equivalents.

The Dyneema Link is produced from FSE Robline SK75 fiber, which is 10 times stronger and lighter than steel, and provides the final connection from the block to the load point. The flexible Dyneema Link provides controlled rotation and 0° or 90° orientation. It connects directly to the head of the block rather than to an intermediate head post. This reduces weight and gives the lowest possible profile while allowing full articulation. Beckets have been carefully designed to minimize height. It is easily fitted and is retained securely by a molded retainer clip. The flexible link can be left with one end attached to the block when fitting — no more lost shackle pins.


  • Sheave: 1-9/16" (40mm)
  • Maximum Line Size: 5/16" (9mm)
  • Maximum Working Load: 715 lb. (325 kg)
  • Breaking Load: 1543 lb. (700 kg)
  • Weight: 1.2 oz. (33 g)


  • Mainsheet systems on spinnaker sheet on dinghies to 5m (16ft)
  • Spinnaker sheets on dinghies, sportsboats and small keel boats to 5m (16ft)
  • Halyard, vang and backstay applications on boats to 8m (26ft)
  • Control line applications on larger yachts


  • Ball Bearings: High compression strength carbon black Acetal
  • Stage 2 Bearing: Glass fiber-reinforced, MoS2 impregnated nylon
  • Frame/Cheeks: Toughened, glass fiber reinforced nylon
  • Sheave: Carbon fiber-reinforced, PTFE impregnated nylon
  • Rope/Link: UV stabilized, multi-strand impregnated SK75 Dyneema®

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