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Harken 57mm Ratchamatic Flip-Flop Block

$212.60 $186.99
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Harken 57mm Ratchamatic Flip-Flop Block

Harken small boat Flip-Flop blocks pivot around the line axis to keep line close to the deck. Hinged construction allows for various lead angles. 

Lightweight, machined 6061-T6 aluminum cheeks pivot on fiber-reinforced plastic chocks. Sheave runs exclusively on a ball bearing system for fast trim and release under any load. Ball bearings, sheave, and sideplates are UV-stabilized with carbon black for maximum protection. 

The Harken Ratchamatic version rolls freely in both directions under low loads and automatically engages a ratchet mechanism as loads increase, giving sailors a holding power of up to 15:1. The ratchet engagement can be adjusted to a higher or lower load depending on the sailor’s strength, sailing style and system usage. 


  Imperial Metric
Sheave Diameter 2 1/4 in 57 mm
Max Line Diameter 3/8 in 10 mm
Max Working Load 500 lb 227 kg
Breaking Load 1,000 lb 454 kg
Weight 5.5 oz 156 g
Length 4 5/16 in 110 mm
Width 2 in 50 mm
Height 2 5/8 in 67 mm