Harken Pulleys & Blocks

Harken Pulleys & Blocks: Engineering That Moves With the Wind

When sailors talk about reducing friction and maximizing mechanical advantage, one name consistently rises to the top: Harken. Their pulleys and blocks are the product of decades of refinement, material science, and collaboration with racers and cruisers at every level — from weekend dinghy enthusiasts to offshore grand prix competitors. Browse the full Pulleys & Blocks category to find the right solution for your rigging system.

A Block for Every Application

Harken offers a complete line of sailboat blocks, pulleys, and low-friction systems suitable for every platform — whether it is a dinghy, keelboat, or megayacht. That range spans an impressive spread of sheave sizes and configurations. Blocks are available in sheave sizes from 16 mm up to 75 mm, in configurations including single, double, triple, soft-attach, fiddle, cam cleat, and becket styles, with working load ranges from under 250 kg all the way to over 1,000 kg.

For performance-focused dinghy sailors, the Micro Block series is a standout. These compact, lightweight, low-friction blocks feature carbon black UV-stabilized Delrin ball bearings, fast trim and release performance, and high-load stainless steel side plates — ideal for cunninghams, outhauls, vangs, traveller controls, and barber haulers. At the other end of the spectrum, the Midrange series steps up to meet the demands of larger vessels: Midrange blocks feature robust construction ideal for high loads found on medium and large offshore boats, with sheaves running exclusively on ball bearing systems for fast trim and release under any load, UV-stabilized carbon-black Delrin components, and a stainless steel side strap across the block head for increased strength and safety.

Signature Technologies Behind Every Block

Harken is widely acknowledged as the global leader in the development of performance blocks featuring ball bearings manufactured in 316 Stainless Steel, UV-stabilized Delrin Acetal Resin, and the hardest, smoothest option: Zirconium/Ceramic, which is seven and a half times stronger in compression than stainless bearings. This tiered bearing approach means sailors can match the block's internal componentry to the demands of their specific system.

Surface protection is equally deliberate. The Harken Hard-Coating process is double the thickness of standard black anodising, providing extra protection against surface damage and corrosion, while Hard Lube-anodized aluminum carries the same corrosion resistance with an added PTFE coating for an even smoother, reduced-friction finish. Carbon black is also applied to Delrin bearings, sheaves, and side plates as a UV-stabilizing additive.

For sailors who need versatility in dynamic conditions, Harken's Ratchet and Ratchamatic blocks offer intelligent load management. The Ratchamatic (automatic ratchet) engages automatically based on the load going through the block — ideal for gybing where pressure releases allow ropes to run freely — and the point of engagement can be fine-tuned with an Allen key. The T2 soft-attach series represents Harken's latest lightweight direction: Harken has continued developing new products with the T2 soft-attach pulleys, and loop, soft-attach, and Ratchamatic pulleys have become especially popular with dinghy sailors for their lighter weight compared to traditional Carbo Air and metal pulleys.

The Element™ block line takes a different structural approach: Harken Element™ Blocks introduce side plates that combine forged aluminum and compound curves for strength, pairing the minimum amount of metal required to protect the sheave with a proven journal bearing. And for high-performance racing applications, the Black Magic series pushes the envelope further — their combination of efficiency, strength, and size makes them the smallest Black Magic blocks yet, appropriate for boats in the 30-foot range.

Choosing the Right Harken Block

Selecting the correct block comes down to three key factors: sheave size (matched to your line diameter), working load (based on the forces in your specific rigging system), and block configuration (single, double, fiddle, or snatch). Harken's lineup is broad enough to cover every intersection of those variables, making it straightforward to build or upgrade an entire running rigging system with consistent, compatible hardware throughout.