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Ronstan RF25109 Series 20 Orbit Block Single Becket Ball Bearing

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

RF25109
07/14/2036 12:34 AM
Sale Price

$12.09

In Stock (10+)

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Usually delivered within 2 days

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Live-in-stock inventory

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Fitment guaranteed

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Product Details
Ronstan RF25109

Lightweight and strong block made for rigging systems that use high-tech lines.

Ronstan’s goal for the Orbit block was to produce a block with an excellent strength to weight ratio—and they nailed it. These blocks weigh in at under 9 grams (.3 oz) but can handle 550 lbs safely. Designed exclusively for lashing installation, the Orbit Series 20 eliminates heavy shackle pin posts and unnecessary metals to reduce weight. To maintain the strength Series 20 blocks are known for, the frame and cheeks have been reinforced with glass fiber nylon and are engineered to accept up to 4mm lashing. Efficiency is provided by the proven two-stage bearing system; light to moderate loads are carried by the 316 stainless steel bearings while heavier static loads are shouldered by a slide bearing. Conventional and high-tech lines run smoothly over the UV resistant acetal sheave. Sailors can have their cake and eat it too with lightweight and strong Ronstan Orbit blocks.

Key Features

  • Excellent strength to weight ratio
  • Two-stage bearing system for efficiency for static and dynamic loads
    • 316 stainless steel ball bearings for moderate loads
    • 316 stainless steel slide bearing for higher static loads
  • Designed exclusively for lashing installations (accepts 4mm lashing)
  • UV resistant high-compression acetal sheave
  • Ideal for dinghy control lines

Ronstan Orbit Blocks® Selection Guide

Sheave DiameterLine CompatibilityShackle Pin Diameter (if applicable)
20mm1/4" (6mm)1/8"
30mm5/16" (8mm)5/32"
40mm5/16" (9mm)5/32"
50mm3/8" (10mm)3/16"

Products specifications

Type

Single

Diameter

1/4 Inch or 6 mm

Mount Type

Rope/Webbing

Ball Bearings

Stainless Steel

Becket

No Becket

Direction

Any

Integral Cleat

No Integral Cleat

Ratchet

Non Ratcheting

Safe Working Load

550 Pounds

Sheave Diameter

3/4 Inches or 19 mm

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