Fast Dispatch, Fast Delivery and a 5 Star Rated Service

Trusted For 12 Years

Over 48,000+ Orders Shipped

90 Day Risk Free Returns

Over 4,000 5 Star Reviews

Price Match Promise

October 25, 2023 1 min read

As part of todays #FridayFocus we are reviewing the 57mm Harken Ratchamatic Ratchet Block. 

A popular product with sailors who want to take advantage of the blocks 10:1 holding power, whether that be on a dinghy, skiff or catamaran.


  • The Harken 57mm Carbo Ratchamatic® block is an automatic load-sensing ratchet pulley that rolls freely in both directions under low loads and automatically engages the ratchet as loads increase. Shifting between ratchet and light-air modes is seamless with no adjustment needed.

    This Harken pulley block is perfect for spinnaker sheets and ropes which need constant adjustment.

    Comes with allen key to adjust the block and when it starts to kick in.


    • Sheave Ø (mm) - 57 mm
    • Length (mm) - 103 mm
    • Weight (g) - 104 g
    • Shackle pin Ø (mm) - 5 mm
    • Maximum line Ø (mm) - 10 mm
    • Maximum working load (kg) - 227 kg
    • Breaking load (kg) - 907 kg
    • Holding power w/180 degree wrap 50 lb (23 kg) - 10:1