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40mm Tii Block

40mm Tii Block

Regular price £36.40
Regular price Sale price £36.40
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High Quality

Flexible, Wallet Friendly Block for Dinghies, Sportsboats & Keelboats

Allen’s Tii-On 40mm Blocks represent great value in a modern, lightweight and high strength package suitable for sheet blocks on a dinghy or sportsboat/keelboat. The central stainless steel axle is designed to be used as a becket giving additional purchase and integration options. The 40mm Sheave will take rope up to 10mm in diameter. For most efficient use we would suggest max 8mm diameter and use the 50mm version if using larger diameter rope. 

The design features a stainless steel loop at the head of the block to stop the block from capsizing once tied into a system as well as reducing the chance of the cheeks splitting apart. The stainless steel head loop also ensures the block stays in the right orientation when being used. The bearings for the Dynamic Tii range ensure a low friction block.  

If splicing onto a boom or other fitting which is wider than the block a cross splice should be used to reduce the chance of splitting the cheeks. The 40mm Tii also comes with a Tii Lock so blocks can be added using a continuous spliced loop - as found on the RS Aero and other classes. 

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Please note these do not come with a soft shackle. Please contact us if you require one. 


  • Sheet Blocks 
  • Boom mounted (continuous loop) Blocks
  • Vang/Kicker Cascades
  • Large Control Line Blocks
  • General Use


  • Impact Resistant Carbon Polymer Cheeks
  • Stainless Steel Ball Bearings
  • Low Friction Polymer Sheave

When attaching a Tii-Block it’s vital that you go through the loop in the head of the block, around the central axle and then back out through the loop at the top. The Tii-block range must be tied like this otherwise it will fail. Please watch the video! 


Model A2040Tii A2040Tii Lock
Break Load (Kg) 800 800
Max Line Diameter 10mm 10mm
Soft Attach Y Y
Weight (g) 34.5 36.5
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