Ronstan Series 75 Core Block - Single [RF74100]
SKU: 24372248717

Ronstan Series 75 Core Block - Single [RF74100]

Sale price$138.47 Regular price$153.85
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Ships within 48 hours ยท Estimated delivery Jul 8 - Jul 13

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Description

Ronstan Series 75 Core Block - Single [RF74100]Series 75 Core Block Single 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

Series 75 Core Blockย™ - Single

Core Blocksย™ 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.

Universal head
The head assembly incorporates a brass bearing washer to provide smooth 360ย™ rotation of the post and shackle. A set screw arrangement allows the head to be locked at 0ย™ or 90ย™.

Shackles are high quality forged grade 316 stainless steel.

Features:

  • Class leading performance and sleek, contemporary styling
  • Excellent dynamic and high static load performance
  • Less than half the friction of the nearest competitor
  • Universal head with full 3-axis articulation
  • Head posts can be locked at 0 or 90 degrees, by using a 2.5mm Hex/Allen Key
  • 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 14M (46')
  • Various control line applications on larger yachts


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 ร˜: 75mm(3")
Max. Rope ร˜: 14mm(9/16")
Pin ร˜: 8mm(5/16")
M.W.L.: 1,500kg(3,300lbs)
B. L.: 3,000kg(6,600lbs)
Weight: 354g(12.5oz)

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 24372248717

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4.8 โ˜…โ˜…โ˜…โ˜…โ˜…
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Kristin
Waukegan, US
โ˜…โ˜…โ˜…โ˜…โ˜… 5
Cute and functional
Color: Brown, Color: Brown
I wanted something to spruce up a corner in my kitchen and these did the trick. They were easy to install and look great. I use mine for small items and they hold up no problem!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on December 25, 2025
S
Verified Purchase
Samantha Schloemer
Massapequa, US
โ˜…โ˜…โ˜…โ˜…โ˜… 5
Shelf
Color: Brown, Color: Brown
Easy to install, clear instructions on how to install. Great quality. Goes well in my space.
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Reviewed in the United States on April 15, 2026
N
Verified Purchase
nelsond7004
Draper, US
โ˜…โ˜…โ˜…โ˜…โ˜… 5
They look good and seem well built.
Color: Brown
These are very well made and look really good. They ended up being too small for my need, but that was my fault on measurements. I would highly recommend if you are looking for corner shelves.
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Reviewed in the United States on March 9, 2026
V
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viar
Louisville, US
โ˜…โ˜…โ˜…โ˜…โ˜… 5
VERY GOOD
Color: Dark Brown
VERY GOOD
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Reviewed in the United States on May 12, 2026
H
Verified Purchase
haley
Chelsea, US
โ˜…โ˜…โ˜…โ˜…โ˜… 4
slightly annoying to hang
Color: Brown
A little annoying to hang but look great and seem to be holding up well! I have heavy plants on them and no issues at all!
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Reviewed in the United States on August 11, 2025

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