Ronstan Series 75 Core Block - Single [RF74100]
SKU: 48506214799

Ronstan Series 75 Core Block - Single [RF74100]

Sale price$138.47 Regular price$153.85
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Ships within 48 hours · 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 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: 48506214799

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Myriam I. Martinez
New York, US
★★★★★ 5
Good quality and durability
Color: C-Black, Size: Model C Rechargeable
It works very well very easy to use I'm very happy with my purchase
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Reviewed in the United States on May 16, 2026
K
Verified Purchase
Kings Kidd
Houston, US
★★★★★ 3
It froths, but is not dependent
Color: C-Black, Size: Model C Rechargeable
While this frother does “froth”, it has many more cons than pros. The ONLY pro is it froths. The cons—only good for a traditional coffee cup. It is not water proof, and the instructions say to keep the “unit “ dry. As you froth, the liquid naturally raises height. If you are trying to use a Togo coffee mug, or thermos type travel mug—it only works well if done it three or four levels to ensure keeping the motor above the liquid. The “rechargeable “ function DOES recharge, however- it may last 1use or a few. It’s VERY inconsistent. And does not seem to be related to how long you allow it to charge. Overall—not a good buy. I had mine maybe 3 months before it quit working. And at 2 months it started becoming spastic. Even after just being charged-it wouldn’t even froth 1cup. AVOID!!
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Reviewed in the United States on May 16, 2026
C
Verified Purchase
Carloslazaroproenza
Massapequa, US
★★★★★ 5
Easy to Use and Works Great
Color: C-Black, Size: Model C Rechargeable, Color: C-Black, Size: Model C Rechargeable
This milk frother works amazingly well! It’s powerful, easy to use, and creates rich, creamy foam in just seconds. The rechargeable design is very convenient, and the battery lasts a long time between charges. It feels sturdy and well-made, and cleaning it is quick and simple. I use it every day for my coffee, lattes, and hot chocolate, and it has exceeded my expectations. If you’re looking for an affordable and effective milk frother, this is definitely a great choice. Highly recommended
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Reviewed in the United States on June 10, 2026
B
Verified Purchase
Bueno lo recomiendo
Cuba, US
★★★★★ 5
Nicec
Color: C-Stand Green, Size: Model C Rechargeable
Es de buena calidad lo recomiendo
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Reviewed in the United States on June 3, 2026
J
Verified Purchase
JESSICA DAY
Boise, US
★★★★★ 5
Love it!
Color: C-Black, Size: Model C Rechargeable
Love mine! No more batteries. I make at least two cups a day and froth my creamer. Love the fact I don’t have to recharge very often.
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Reviewed in the United States on May 19, 2026

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