72mm Synchro Halyard Block
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LEWMAR72mm Synchro Halyard Block


In stock online.
Model # 13061981 | Mfg # 29927221BKUPC # 743683203893
72mm Synchro Halyard Block


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72mm Synchro Halyard Block

Name Value
Becket No Becket
Diameter 1/2 Inch or 13 mm
Direction Any
Integral Cleat No Integral Cleat
Mount Type Fixed Lashing Eye
Ratchet Non Ratcheting
Safe Working Load 2420 Pounds
Sheave Diameter 72 mm
Type Single
Weight 6.93 Ounces

Product Overview

A unique block that is synchronized with running rigging systems.

The 72mm halyard block features a toggle head to secure to mast base studs commonly on contemporary racer/cruiser sailboats. Ideal for halyard turning blocks, the larger sheave diameter works well with lines up to 1/2".

Synchro blocks combine geometry, sheave ratios and a unique Free Spin bearing to deliver performance that’s comparable to ball and roller bearing blocks used in racing—but at a more affordable price. Designed to optimize the relationship between block and line, these blocks have self-aligning features to maximize efficiency and reduce wear to both line and block. An innovative sliding mechanism controls shackle post swivel. With the flick of a switch select between full 360° free rotation or one of two fixed settings (0° or 90° to sheave axle). Both fixed positions provide 30° of rotational “float” to allow the block to self-align to the system.

Synchro blocks use a larger sheave that features the Free Spin bearing. The bigger diameter sheave prevents distortion and reduces line wear while the Free-Spin bearing handles higher static loads. A stainless steel shackle post and framework supports the glass fiber reinforced cheeks to increase block strength while minimizing overall weight. The molded cheeks guide the line and prevent wedging.

Designed to be synchronized with your boat’s running rigging systems, Lewmar Synchro blocks are an ideal choice for the sailor looking to get more for less: racing features at a cruising price.

Key Features

  • Plain bearing block with ball bearing like performance
  • Highly efficient free-spin bearing reduces drag
  • Self-aligning head allows 30° of float (in locked setting) to reduce wear on line
  • Stainless steel strap for added strength and durability
  • Adjustable swivel settings: full rotation, parallel with the pin and perpendicular with the pin
  • Stiff cheeks guide line to prevent wedging
  • Compatible with 3/8"—1/2" lines
  • Standard equipment on newer racer/cruiser sailboats including Beneteau
  • Ideal for high static loads
    • External halyards
    • Halyard turning blocks (designed to secure to studs in mast base)

Selection Guide

Sheave DiameterLine RangeToggle Pin Diameter
50mm1/4"—3/8" (6mm—10mm)3/16"
60mm5/16"—3/8" (8mm—10mm)7/32"
72mm3/8"—1/2" (10mm—12mm)5/16"
90mm1/2"—9/16" (12mm—14mm)25/64"


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