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BLOCK,CHEEK         40mm



$51.98 CAD
In Stock


Series 40 Ball Bearing Orbit Block™, Lightweight Cheek

Lightweight single sheave 40mm cheek block, requires 3 x 4mm (5/32") fasteners


Ultra Lightweight.

Low friction 2-stage Orbital ball bearing system.

Highest working load in its class.

Low profile and compact.

High performance cleatingBase suits curved mounting surface.

Low mounting points for maximum strength.


Product Specifications
B.L. (kg) 700
M.W.L. (kg) 325
Max. Rope diameter (mm) 9
Weight (g) 32
Fastener Ø (mm) 4
Qty. Fasteners 3

Product Information

Kilogram for kilogram of working load, BB and RT Orbit Blocks™ are the world’s lightest. The unique orbital design allows the bearing to only be in the active areas of the floating sheave. This minimises the mass of the inactive return race and hub. Weight and bulk are further reduced in the different block configurations. The ball bearing single and becket block has a through-sheave becket arrangement. The result? The lowest weight possible. Multi-sheave blocks have only single intermediate cheeks and an ultra-light and efficient head arrangement. This gives a 30% weight saving advantage over the nearest competitor. Other brands just link together their single blocks. This results in unnecessary double cheeks between each sheave, held together by a heavy steel channel across the top of the block.

Highest working load in its class
. The orbital ball-bearing arrangement gives the largest possible bearing race diameter. This maximises load performance. The proven Ronstan 2-stage bearing system features high compression grade acetal ball bearings and a secondary full-contact bearing. This gives minimum friction across the full working load range. The floating sheave and bearing system is supported by a fibre-reinforced load frame. The design was computer modelled to be stress optimised.

Recommended fasteners - 3 x 4mm (5/32") countersunk head screws.



  • Mainsheet systems and spinnaker sheets 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.


  • Sheave: Carbon fibre reinforced, PTFE impregnated nylon.
  • Ball bearings: High compression strength acetal.
  • Stage 2 bearing: Glass fibre reinforced, MoS2 impregnated nylon.
  • Frame/cheeks: Toughened, glass fibre reinforced nylon.

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