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

Ronstan Series 75 Core Block - Single [RF74100]

Sale price$138.47 Regular price$153.85
Save 10%

Shipping Estimate
USA
  • USA
  • CAN

Ships within 48 hours · Estimated delivery Jul 8 - Jul 13

Promo Codes Available:

For Your Every Summer RSVP, with Code: SUMMER15

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: 24372248717

Discover Niche Categories That Outsell

Top-Converting Item to Boost Your Average Order

4.9 ★★★★★
Based on 71 reviews
Sort
Highest Rating
Newest First
Oldest First
Product Reviews
M
Verified Purchase
Megan Cusack
Chelsea, US
★★★★★ 5
Love these floating shelves!
Color: Oak, Number Of Shelves: 2, Size: 36"W x 6.5"D
These shelves are perfect for my kitchen! They were easy to install. All the hardware was included. They are durable and sturdy and gave my kitchen wall an instant face lift!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 14, 2026
A
Verified Purchase
A. Tucker
Battle Creek, US
★★★★★ 3
Holes in brackets are not spaced for studs!
Color: White, Number Of Shelves: 2, Size: 67"W x 6.5"D
So the quality of this not great, but good enough and they look nice enough on the wall. However, the bracket holes are not spaced at 16" intervals. WTF? I'm not sure who designed this thing. The molly plugs that came with it look OK, but to play it safe I used a cobalt steel drill bit and made my own holes in the bracket. Easy enough with some wd40. My other pick with this is that the screws to anchor the shelf to the bracket are black and and very obvious... they should have supplied some kind of cap.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on January 31, 2026
A
Verified Purchase
Ashley
Battle Creek, US
★★★★★ 5
Nice, make sure the measurements are what you want!
Color: Black, Color: Black
I like these shelves, just make sure to read the measurements , because they are a little narrow, but perfect for what I used them for. They added a sleek look to my wall. I'm a very plain Jane kind of person and I've gotten compliments from my friends. I used them to put my crystal collection on and they are holding up. I did use these new screws and anchors from tiktok to hold them up, not the screws these came with because I don't like the plastic anchors. The size is perfect and with a little help with straightness, I got four up out of six.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 11, 2026
M
Verified Purchase
Maria
Alexandria, US
★★★★★ 5
Me encantó el producto
Color: White, Color: White
Encantada 💜me gusto mucho lo recomiendo
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 20, 2026
J
Verified Purchase
Jarvis Buczynski
Houston, US
★★★★★ 1
Glue separated within five minutes of being hung up
Color: White
I do not recommend. As I was hanging them, the shelves looked like they were already going to separate. I hung them up and I put a couple books on a few different ones as well as some trinkets not weighing even 5 pounds (so not even close to the weight). Within five minutes. One of the shelves snapped. They look okay, are light and are super easy to use, but the quality is horrible. I would say the best part about this is the hardware and mini levels it comes with. Definitely not worth it. I’m sure you can find something better for the price.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 29, 2026

recommand products