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Harken 381 29mm Carbo Air Double Block Fixed Head

Manufacturer

Harken

<h3>About Harken: Performance Marine Hardware Since 1967</h3><p><strong>Harken</strong> is one of the most recognized names in performance marine hardware, with a legacy stretching back to 1967. <a href="/14853-harken">Harken</a> was founded in a 60-foot trailer by brothers Peter Harken and Olaf Harken, who set out to engineer better sailboat hardware than anything the market had to offer. Their early breakthrough — the plastic recirculating ball bearing block — redefined how sailors managed lines under load and launched a brand that would go on to dominate competitive sailing at the highest levels.</p><p>Headquartered in Pewaukee, Wisconsin, and with a major manufacturing facility in Limido Comasco, Italy, Harken operates as an employee-owned company with distribution spanning 48 countries. From club racing dinghies to grand prix offshore programs, Harken hardware has been aboard winning boats for decades — making its Olympic and America's Cup debuts in 1976 and 1977, respectively.</p><h3>A Full Range of Marine Hardware</h3><p>Harken's product lineup is broad by design. The company works hard to be the technological leader in sailboat blocks, deck hardware, winches, and hydraulics, as well as safety and rescue equipment and services. Their marine catalog includes small boat and big boat blocks, travelers and genoa leads, mainsail and headsail handling systems, winches, hydraulics, mooring solutions, and a robust line of spare parts and accessories.</p><p>At the core of it all are Harken's renowned <a href="/14853-harken-pulleys-blocks-200822">Pulleys &amp; Blocks</a> — the product category that started it all. Whether you're outfitting a high-tech racing dinghy or a bluewater cruising yacht, Harken blocks are engineered for high-load capacity, corrosion resistance, and the smoothest possible operation. The lineup spans sheave sizes from 16 mm all the way to 75 mm, with single, double, triple, fiddle, and soft-attach configurations to cover virtually every application on deck.</p><p>Beyond sailing, Harken also produces a dedicated line of sportfishing <a href="/14853-harken-pulleys-blocks-202394">Pulleys &amp; Blocks</a> engineered for the unique demands of offshore fishing. These compact, high-load pulleys are built for outrigger systems, dredge rigging, and heavy-duty line management — bringing the same patented bearing technology that excels on race courses to the rigors of the fishing cockpit.</p><h3>Why Sailors Trust Harken</h3><p>What sets Harken apart is a relentless commitment to engineering. Each product category is developed with input from top sailors, sailmakers, and boat designers — and the results speak for themselves on race courses worldwide. Harken hardware is a consistent fixture on America's Cup campaigns, Volvo Ocean Race fleets, Olympic classes, and everything in between. For cruisers, that race-proven performance translates into gear that is more reliable, longer-lasting, and more responsive than the alternatives.</p><ul><li>Employee-owned company with decades of marine engineering expertise</li><li>Manufacturing in the USA and Italy, with global distribution in 48 countries</li><li>Patented bearing systems engineered for high loads and minimal friction</li><li>Product lines covering everything from small dinghies to superyachts</li><li>Trusted at the Olympic Games and America's Cup since the 1970s</li></ul>

Part Number

381
06/02/2036 5:30 PM
Sale Price

$33.58

In Stock (10+)

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Usually delivered within 2 days

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No Hassle Returns

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Live-in-stock inventory

Fitment guaranteed

Fitment guaranteed

Product Details

The Harken 381 is a 29mm Carbo Air® Double Block with fixed head design, engineered for high-performance sailing applications requiring 2:1 or 3:1 purchasing systems. This award-winning block combines exceptional strength with ultralight weight, making it ideal for racers and performance sailors who demand reliability without compromising speed.

Revolutionary Carbo Air® Construction:

Harken's Carbo Air® technology delivers a strength-to-weight ratio that sets the industry standard. The fiber-reinforced composite sideplates are UV-stabilized for long-term durability and designed specifically for the small-diameter, high-tech lines preferred on racing boats. This innovative design earned both the prestigious Dame Award and Sail Magazine's Freeman-Pittman Award for marine innovation.

Performance Advantages:

  • 30% lighter than equivalent conventional blocks
  • 60% stronger than comparable Classic series blocks
  • Double sheave configuration for versatile purchase systems
  • Low-friction operation for smooth, easy trimming
  • Compact footprint perfect for space-limited applications
  • Fixed head design provides secure, stable mounting

Specifications:

  • Sheave Diameter: 1 1/8" (29mm)
  • Maximum Line Diameter: 5/16" (8mm)
  • Maximum Working Load: 660 lbs (299 kg)
  • Breaking Load: 1,625 lbs (737 kg)
  • Weight: 1.2 oz (34 g)
  • Overall Length: 2 1/8" (54mm)

Applications:

Ideal for jib and mainsheet systems on high-performance dinghies, control lines on small keelboats, and any application where minimizing weight while maximizing strength is critical. The compact size and high working load make these blocks perfect for modern racing setups using high-tech, low-diameter lines.

Products specifications

Type

Double

Diameter

5/16 Inch or 8 mm

Length

2 1/8 Inches

Mount Type

Fixed Lashing Eye

Ball Bearings

Plastic

Becket

No Becket

Direction

Any

Integral Cleat

No Integral Cleat

Ratchet

Non Ratcheting

Safe Working Load

660 Pounds

Sheave Diameter

29 mm

Friendly to do buss. with!

Great price and service.

Thanks I had received my package

Great

Simple fast please leave me tracking number

I found what I needed at a reasonable price.

Delivered on time as ordered

I may need to return the unopened part and i don't see the policy and procedure. Ill have to search on the site page. All legit solid businesses I've worked with in the past made this very clear and up front. Not to say you didn't I just haven't looked yet and its not in your face obvious.

It was easy to place the order and delivery of order was prompt (within 3 days).

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