SKU: 89880949312

Ronstan Series 75 Core Block - Single [RF74100]

Sale price$138.47 Regular price$153.85
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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 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 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 360™ rotation of the post and shackle. A set screw arrangement allows the head to be locked at 0™ or 90™.

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 Ø: 75mm(3")
Max. Rope Ø: 14mm(9/16")
Pin Ø: 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: 89880949312

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hazard2k
Lexington, US
★★★★★ 5
True copper battery cables that are high quality
Size: 10ft, Color: 4awg
I love having heavy duty cable on hand for my cars. It's so nice to be able to make your own starter and alternator cables when restoring cars. These cables are 100% copper, not CCA (copper clad aluminum) like many others are. Copper is far superior for conductivity and handling higher loads. The rubber on the cable is thick and yet very flexible..it's clearly marked and seems very durable. I like to use a hydraulic crimping tool and then add marine grade heat shrink tubing with the adhesive inside of it to keep it as weatherproof as possible.
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Reviewed in the United States on May 10, 2026
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Ken H
San Leandro, US
★★★★★ 5
Easy to work with
I bought this to wire up an airplane I built. I had to cut it into 10 separate pieces and crimp and solder lugs to each end. It was just the right length for what I needed and I'm very happy with the results.
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Reviewed in the United States on January 5, 2024
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Quinn Harrison
Draper, US
★★★★★ 5
Good product. I will buy again.
Great value. It did show up covered in small fiberglass particles which was a bit annoying.
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Reviewed in the United States on March 10, 2021
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Scott Yeh
Draper, US
★★★★★ 5
Excellent true copper wires 6 AWG cable
I bought them to use on sub-wiring job running 12vdc from positive terminal to custom fuse box of my van. This cable maybe mainly for welding machine, but it works great for my project with its true copper wires and high flexibility.
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Reviewed in the United States on July 7, 2019
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S. Steves
Chelsea, US
★★★★★ 4
Used for 140 amp alternator to battery
Before that wire would get hot to the touch. Carry’s the current like a chap. Important that it is copper and multiple braided
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Reviewed in the United States on October 8, 2023

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