Ronstan Series 45 Core Block™ - Single - Swivel Shackle Head RF44100

Series 45 Core Block™ - Single - Swivel Shackle Head

Core Blocks™ are a true all round solution. A tuned 2-stage bearing system provides excellent performance across the full working load range with an integrated thrust bearing feature and the resilience to handle high dynamic or static loads. Acetal sheave, alloy cheeks and stainless fixings complete the durable package. For reliability and a long service life, these blocks are the right choice for sheets, halyards and control line applications for cruising and racing.

Universal Bearing
Dynamic and high static load performance

The Ronstan Universal Bearing incorporates our proven 2-stage bearing system

Stage 1 - Under moderate loads, Acetal ball bearings ensure minimum friction.

Stage 2 - Under heavy loads, where deformation of ball bearings alone would result in increased friction, a sliding Acetal bearing on a polished stainless steel race takes over, maintaining low friction performance.

Additionally the ball bearings are configured to act as a thrust bearing between the sheave and cheeks, preventing the sheave from rubbing on the cheeks and causing friction when the line lead in and out of the block isn't perfect. Particularly important for cheek blocks.

Alloy Cheek Plates
Block cheeks are manufactured from the highest quality alloy for maximum strength. Material optimisation and the cut-away design minimises weight and allows easy fresh water rinsing of salt and debris from the bearings. Cheek design has been further styled with flaring at the block throat and reduced gap between the cheek and sheave, minimising rope wear.

Features:

• High dynamic and static load capacity
• Efficient 2-stage bearing system
• Ball bearings to counteract side thrust loads
• Class leading performance and sleek, contemporary styling
• Durable aluminium alloy cheek plates
• Central hub hole can be used as a becket take-off or tie-up point

Applications:

• Ideal for mainsheet, halyard and spinnaker sheet applications on boats to 10M (33')
• Various control line applications on larger yachts
• Alloy sheave models are available for use with wire

Materials:

• Sheave: U.V. stabilized Acetal
• Cheek body: Aluminium Alloy
• Ball Bearings: High compression strength carbon black Acetal
• Shackle, head post & hub: Grade 316 stainless steel

Specifications:
Sheave Ø: 45mm(1-3/4")
Max. Rope Ø: 12mm(1/2")
Pin Ø: 5mm(3/16")
M.W.L.: 700kg(1,540lbs)
B. L.: 1,400kg(3,090lbs)
Weight: 104g(3.6oz)

Shipping
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Processing and dispatch
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Duties, taxes, and support
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Quality Boat Parts is a reseller. Many items include a manufacturer’s warranty, and all warranty service is handled directly by the manufacturer. We do not manage or administer warranty claims on behalf of customers.

Warranty terms, coverage, and duration are set by each manufacturer. Issues involving defects, repairs, or replacements must be addressed with the manufacturer’s support team. When available, the warranty period is listed on the product page. If it is not shown, contact us or the manufacturer for details before purchasing.

To start a claim, the customer must contact the manufacturer and follow their process. Keep your proof of purchase and original packaging, and register the product if the manufacturer requires it, as these are often needed for warranty service.

We are happy to help you find the right contact or documentation, but we cannot decide outcomes or intervene in claim resolutions. For guidance, email cs@qualityboatparts.com.