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Ronstan RF20100 Series 20 Single Block 20mm with Shackle Head

Manufacturer

Ronstan

<h3>About Ronstan – A Legacy Built on the Water</h3><p>Few names in the sailing world carry as much weight as Ronstan. <strong>Founded in 1953</strong> by Ron Allat and Stan Lenepveu, the company began as a small boatbuilding operation in Highett, a suburb of Melbourne, Australia. What started as handcrafting custom yacht fittings for fellow sailors at the nearby Black Rock Yacht Club steadily grew into one of the most respected sailboat hardware manufacturers on the planet. The brand name itself is a nod to its founders — Ron and Stan — whose passion for sailing and precision craftsmanship shaped the company's DNA from day one.</p><p>Today, <strong>Ronstan International</strong> is a globally recognised manufacturer and supplier of sailboat hardware, rigging components, winches, sailing gear, and accessories, with its head office remaining in Braeside, Victoria, Australia. The company has established manufacturing facilities in Australia, Denmark, and Indonesia, along with sales offices in the United States, and distributes products to sailors in over 40 countries around the world. In November 2023, Ronstan joined <strong>Groupe Wichard</strong>, aligning with an industry leader whose portfolio spans more than ten world-renowned brands in the sailing and safety markets — a move that further strengthens Ronstan's global reach and product offering.</p><h3>Engineered for Every Sailor, Proven at the Highest Levels</h3><p>Ronstan's reputation spans the full spectrum of sailing — from first-time dinghy sailors to elite competitors at the America's Cup and Olympic Games. The brand serves as the official supplier to the Australian Sailing Team, and Ronstan hardware has appeared aboard medal-winning boats across multiple Olympic campaigns. That pedigree at the pinnacle of racing directly fuels the innovation available to everyday sailors: the demanding performance requirements of top-tier competition have driven many of the technical breakthroughs found throughout Ronstan's broader product range.</p><p>The company's catalog encompasses well over 2,000 products, including pulley blocks, traveller systems, furlers, rope cleats, stainless steel fittings, shackles, snap shackles, and winches. Whether you're outfitting a small racing dinghy, a family cruiser, or an offshore race yacht, Ronstan offers hardware designed and tested to perform in real-world conditions. Their in-house capabilities span design, engineering, precision injection moulding, CNC machining, metal pressing, and assembly — all of which contribute to the consistent quality sailors have come to expect from the brand.</p><h3>Top Ronstan Product Categories</h3><p>Among Ronstan's most popular product lines are their <a href="/11561-ronstan-tiller-extensions-accessories-202641">Tiller Extensions &amp; Accessories</a>, which encompass both their renowned carbon fibre and alloy tiller extension ranges. Whether you need a lightweight, rigid fixed-length stick or a telescopic option for adjustable reach, Ronstan's tiller extensions are engineered for decisive helm response and positive grip in all conditions. Complementing these are Ronstan's <a href="/11561-ronstan-tiller-extensions-accessories-201068">Tiller Extension Accessories</a> — including universal joints, retaining clips, and end knobs — that allow sailors to fine-tune their setup or replace worn components with ease.</p><p>Ronstan also produces a well-regarded line of <a href="/11561-ronstan-fairleads-201944">Fairleads</a>, designed to guide lines smoothly across a boat's deck. Available in UV-stabilised nylon and with optional stainless steel liners for added strength and longevity, these practical fittings are a staple of both dinghy and keelboat rigging setups worldwide.</p><h3>Why Choose Ronstan?</h3><ul><li><strong>70+ years of marine hardware expertise</strong> rooted in Australian sailing culture</li><li>Products trusted by Olympic sailors, offshore racers, and cruising sailors alike</li><li>Over 2,000 products covering everything from small dinghy fittings to superyacht systems</li><li>Advanced manufacturing across three international production facilities</li><li>Part of Groupe Wichard, adding complementary product depth and global support</li></ul>

Part Number

RF20100
06/21/2036 6:36 AM
Sale Price

$17.12

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Product Details

The Ronstan Series 20 single block with shackle head delivers high-performance ball bearing efficiency for dinghy and small keelboat sailors who demand precise feedback from their control lines. This lightweight 20mm block features an innovative two-stage bearing system that maintains smooth, low-friction operation under both moderate and high loads.

Two-Stage Bearing System:

At the heart of the RF20100 is Ronstan's unique dual bearing design. Acetal ball bearings provide exceptional efficiency under moderate loads, delivering the sensitivity needed to detect subtle wind changes. As forces increase, a plain acetal bearing running on a stainless steel race takes over, preventing ball bearing distortion while maintaining impressively low friction.

Durable Construction:

  • UV-stable acetal sheave combines strength with light weight for long-lasting performance
  • Fiber-reinforced nylon cheeks add rigidity while minimizing overall weight
  • 316 stainless steel load straps provide enhanced strength where it matters most
  • Included shackle features low-profile pin head to prevent snagging on smaller diameter lines

Ideal Applications:

  • Dinghy sheets and control lines
  • Halyard tuning systems and Cunninghams
  • Backstay systems on dinghies and smaller keelboats
  • Boom vangs and cascade systems

Specifications:

  • Sheave diameter: 20mm
  • Compatible with 1/4" (6mm) line
  • Shackle pin diameter: 1/8"
  • Designed for moderate to high static and dynamic loads

The RF20100 is a versatile block perfect for sailors who need smooth operation and reliable performance in hand-held control line applications.

Products specifications

Type

Single

Diameter

1/4 Inch or 6 mm

Mount Type

Swivel Shackle

Ball Bearings

Stainless Steel

Becket

No Becket

Direction

Any

Integral Cleat

No Integral Cleat

Ratchet

Non Ratcheting

Safe Working Load

550 Pounds

Sheave Diameter

20 mm

The web site was easy and it said my part is in stock. I'm a little suspicious since no one else has it in stock. I will change rating from 5 star to 1 star if it turns out you don't really have the part!!!

awsome

Good experience

Quick and easy.great price

Quick checkout offering Amazon or PayPal checkout very convenient

Very good system. Thank you.

Initially I was somewhat disappointed with this site's turnaround between the purchase and shipping dates (aprox 3 days) on my merchandise. After vocalizing about the issue autoplicity's customer service actually approached me to correct the problem. With other such issues from other online stores I have had to track down someone to contact for help and then go through an ordeal to obtain assistance. I would use this site again based solely on their proactive service.

easy enough so far

Very easy. Tried O'Reilly's and that was a pain. I'm ordering from Australia.

I have not received my order because it is still the same day I ordered therefore i can not comment on shipping. However I do not worry about that process at all due to the professional look autoplicity.com shows through their website. The prices are the website are the lowest I've found and in-stock quantity is great allow me to find every I needed.

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