Harken -12 Integral Hydraulic Backstay Adjuster

Brand: Harken
Product Code:

Harken’s integral hydraulic backstay adjuster provides the power to optimize sail shape quickly. The cylinder features a built-in, double-acting pump that delivers oil when the handle is both pushed and pulled. This moves oil through the system twice as fast as single-acting pumps on other integrals.

Assemblies include a hardcoat-anodized aluminum cylinder and pump, valve, gauge, and stainless pump handle with three attachment options: pin installs handle permanently; O-ring secures handle in socket, but is not permanent; nonlocking handle installs without O-ring and roll pin. All pins and plugs are stainless steel. Cylinders include a clevis on both ends. Standard eye-jaw toggles fit all Harken® cylinders.

The pressure release knob turns clockwise to close and pump, counterclockwise to release. When closing the pump, the knob cannot be over-tightened by hand, preventing damage to the valve. Release speed depends on how far open the knob is turned. Pressure relief is factory set to prevent crew from over-tensioning the backstay.

An analog gauge with pressure increments reading 0-5 (0-5000 psi) is prominently mounted at the top of the cylinder. The gauge adjusts to four positions for easy viewing from the cockpit.

- Size-12 
Maximum wire Ø (mm)8 mm
Maximum wire Ø (in)5/16 in
Stroke (mm)385 mm
Stroke (in)15.2 in
Pin center length (closed) (mm)832 mm
Pin center length (closed) (in)32.8 in
Weight (kg)4.92 kg
Weight (lb)10.8 lb
Gap/pin Ø (mm)15.9 mm
Gap/pin Ø (in)5/8 in
Pull force @ 1000 psi/69 bar (kg)952 kg
Pull force @ 1000 psi/69 bar (lb)2098 lb
Pull force @ 2000 psi/138 bar (kg)1904 kg
Pull force @ 2000 psi/138 bar (lb)4197 lb
Pull force @ 3000 psi/207 bar (kg)2855 kg
Pull force @ 3000 psi/207 bar (lb)6295 lb
Pull force @ 5000 psi/345 bar (kg)4759 kg
Pull force @ 5000 psi/345 bar (lb)10492 lb
Breaking load (kg)9518 kg
Breaking load (lb)20984 lb
FootnoteFor pin center length open add stroke length to pin center length closed., Max relief setting is 5, 000 psi / 345 bar., Rod ends (forks) included in weights.