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Ronstan RF51200 Series 50 Double Block with Swivel Shackle Head

Manufacturer

Ronstan

<h3>Ronstan: Precision Sailing Hardware Built for Every Sailor</h3><p><strong>Ronstan</strong> is one of the most respected names in sailboat hardware — and with good reason. <a href="/11561-ronstan">Ronstan</a> traces its roots back to 1953, when two Australian sailors, Ron Allatt and Stan Lenepveu, founded Ronstan Marine Equipment Pty Ltd in Melbourne, Australia. What started as a passion project supplying handcrafted yacht fittings to their local sailing club gradually grew into a global enterprise recognized for engineering excellence and real-world performance.</p><p>Today, Ronstan is headquartered in Braeside, Victoria, Australia, with international offices in the United States and Denmark, and production facilities across three continents. The brand distributes to more than 40 countries and handles upwards of 4.9 million units out of its Melbourne facility every year. In November 2023, Ronstan joined Groupe Wichard, further cementing its place among the world&apos;s most influential marine hardware groups.</p><h3>Engineering That Performs On the Water</h3><p>What sets Ronstan apart from generic marine suppliers is its deep commitment to innovation and in-house manufacturing capability. Ronstan&apos;s engineering teams — spread across Australia, the United Kingdom, and Denmark — draw on diverse sailing traditions to develop products that meet the demands of wildly different markets: from club dinghy racers to offshore bluewater cruisers. The brand&apos;s catalog spans blocks, winches, travelers, furling systems, batten systems, stainless steel rigging hardware, and a full suite of deck gear. Ronstan is also the official hardware supplier to the Australian Sailing Team.</p><p>The brand&apos;s in-house manufacturing includes precision CNC machining of aluminum, brass, and stainless steel, as well as advanced plastic injection molding using high-performance engineering polymers — including composites reinforced with up to 60% long-strand glass and carbon fiber. This vertical integration means Ronstan controls quality from design to delivery.</p><h3>Core Product Categories</h3><p>Three categories stand out as workhorses of the Ronstan lineup. <a href="/11561-ronstan-fairleads-200387">Ronstan Fairleads</a> are purpose-designed to guide, contain, and correct the lead angle of control lines across a range of deck configurations — a deceptively simple piece of hardware that plays a critical role in clean, friction-free sail handling. For securing lines under load, <a href="/11561-ronstan-cleats-200268">Ronstan Cleats</a> offer a comprehensive range spanning jam cleats, vee cleats, and the brand&apos;s well-known C-Cleat&trade; and T-Cleat&trade; cam cleat families, each engineered for reliable cleating and easy release in all conditions. Completing the rigging equation, <a href="/11561-ronstan-shackles-200937">Ronstan Shackles</a> — including the innovative Triggersnaps&trade; snap shackle range — are individually proof-load tested and designed for intuitive one-handed operation, making them a trusted choice for racers and cruisers alike.</p><h3>From Dinghies to Maxis</h3><p>One of Ronstan&apos;s most distinctive qualities is its breadth. The same brand that equips Olympic-class dinghies also supplies hardware to some of the largest and fastest offshore racing yachts in the world. Whether you&apos;re outfitting a small club boat or a serious offshore campaigner, Ronstan&apos;s catalog has a solution engineered to the right weight, load rating, and finish for the task at hand.</p>

Part Number

RF51200
09/12/2036 11:04 AM
Sale Price

$72.59

In Stock (7)

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Usually delivered within 2 days

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Product Details

The Ronstan Series 50 All Purpose Double Block delivers exceptional performance for cruising and racing sailboats up to 33 feet. This versatile marine block features self-lubricating Acetal polymer sheaves running on polished stainless steel races, providing smooth operation under both dynamic and high static loads. The swivel shackle head allows full 360-degree rotation for optimal line management.

Key Features:

  • Double sheave configuration with 2-inch (50mm) diameter sheaves
  • Exceptionally high working load of 2,200 lbs (1,000 kg) with 4,410 lb breaking strength
  • Self-lubricating Acetal polymer sheaves ensure low friction and extreme durability
  • Slotted pin shackle design eliminates fouled lines
  • Non-locking swivel head provides 360-degree rotation
  • Low maintenance design for long service life

Construction:

  • Grade 316 stainless steel load strap for superior corrosion resistance
  • Impact and UV resistant fiber-reinforced Nylon cheeks
  • Polished stainless steel races for smooth sheave operation
  • 1/4-inch (6mm) pin diameter

Applications:

  • Mainsheet and halyard systems
  • Vang and spinnaker control lines
  • General sheet and control line applications on boats up to 33 feet (10m)

Specifications:

  • Maximum rope diameter: 1/2 inch (12mm)
  • Weight: 9.0 oz (255g)
  • Maximum working load: 2,200 lbs (1,000 kg)
  • Breaking load: 4,410 lbs (2,000 kg)

Ideal for sailors demanding reliable, high-performance blocks for their control line systems, the Ronstan RF51200 combines durability with smooth, low-friction operation.

Products specifications

Type

Double

Diameter

1/2 Inch or 13 mm

Mount Type

Swivel Shackle

Ball Bearings

Low Friction Bearings

Becket

No Becket

Direction

Any

Integral Cleat

No Integral Cleat

Ratchet

Non Ratcheting

Safe Working Load

2200 Pounds

Sheave Diameter

50 mm

good prices

best price on a Tru-cool H7B transmission cooler

Shall update after receiving the part and being able to use it

Easy and accurate.

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