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Description
Ronstan 60mm Mast Base, 8mm (5/16") Clevis Pin Head Core BlockProduct Description Ronstan 60mm Mast Base, 8mm (5 16") Clevis Pin Head Core Block Features Class leading performance and sleek, contemporary styling Excellent dynamic and high static load performance Less than half the friction of the nearest competitor Durable aluminum alloy cheek plates Central hub hole can be used as a becket take off or tie up point Suits attachment to 14mm (9 16) wide mast collar post Removable 8mm (5 16) clevis pin at head
Product Description
Ronstan 60mm Mast Base, 8mm (5/16") Clevis Pin Head Core Block
Features
Class leading performance and sleek, contemporary styling
Excellent dynamic and high static load performance
Less than half the friction of the nearest competitor
Durable aluminum alloy cheek plates
Central hub hole can be used as a becket take-off or tie-up point
Suits attachment to 14mm (9/16”) wide mast collar post
Removable 8mm (5/16”) clevis pin at head
Measurements
Sheave Ø - 2 3/8 in. (60 mm)
Max. Rope Ø - 1/2 in. (12 mm)
Max. Cable Ø - in (mm)
Pin Ø - 5/16 in. (8 mm)
M.W.L. - 2200* lb. (1000* kg)
B. L. - 4410* lb. (2000* kg)
Weight - 6.4 oz. (182 g)
Product Information
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 optimization and the cut-away design minimizes 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, minimizing rope wear.
Applications
Ideal for mainsheet, halyard and spinnaker sheet applications on boats to 12m (40ft).
Various control line applications on larger yachts.
Alloy sheave models are available for use with wire.
Materials
Sheave: U.V. stabilized Acetal or anodized aluminum (AW models)
Cheek plates: Aluminum alloy
Ball Bearings: High compression strength carbon black Acetal
Pin: 2205 stainless steel
Features
Measurements
Sheave Ø - 2 3/8 in. (60 mm)
Max. Rope Ø - 1/2 in. (12 mm)
Max. Cable Ø - in (mm)
Pin Ø - 5/16 in. (8 mm)
M.W.L. - 2200* lb. (1000* kg)
B. L. - 4410* lb. (2000* kg)
Weight - 6.4 oz. (182 g)
Product Information
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 optimization and the cut-away design minimizes 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, minimizing rope wear.
Applications
Materials
Shipping Notes
- Free Standard Shipping on $100+ Orders to the USA.
- Except Preorder products are shipped in 48 hours.
- Delivery to the USA:
- 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
4.7 ★★★★★
Based on 24 reviews
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Product Reviews
★★★★★ 5
Sasstie Wedge Pillow
Color: Cool Grey, Size: 24x24x12 inch
Perfect. I used it when I was recovering from hip surgery. Relieved a lot of pain in my hip and knee at a time when I needed relief.
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Reviewed in the United States on May 30, 2026
★★★★★ 5
Comfortable, firm, great for positional sleep therapy
Color: Cool Grey, Size: 24x24x12 inch
This is just what I needed to breathe better in my sleep, my doctor recommended a pillow like this for sleep apnea symptoms. I have an upcoming surgery too, so i'm glad I was able to test it out a week prior and see how it can help me prop up in bed. Feeling better about my upcoming recovery knowing i'll have this great pillow to support me!
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Reviewed in the United States on April 4, 2026
★★★★★ 5
Literally perfect and exactly what I needed!
Color: Cool Grey, Size: 24x24x12 inch
I can't recommend this enough! It was exactly what i was looking for! I have an annoying habit of researching everything for months before I purchase something that will get used this often. I finally decided on this one and I was very pleasantly surprised. I needed a wedge pillow to put at my back while sitting in bed. Mostly for when I'm working on my laptop. This one was the perfect height and perfect fit for me.I'm a female that is 5'4 and weigh about 117pds. I wanted something firm enough to support my back, and this most certainly does! It had a very pleasant appearance with the light gray sides. It has a removable cover I can take off and wash when needed. It's portable enough to move from room to room, also works great on my couch and it has amazing versatility. It can also be used as a pillow for someone that might need to sleep at a slight incline. It also works if you need to prop your legs up.
It came vacuum packed. Once opened It said to let is sit for at least 24-48 hrs to give it time to properly inflate. For me, It plumped right up immediately! Again, from someone that does her research, if your looking for something like this at a reasonable price, this is it!
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Reviewed in the United States on May 10, 2026
★★★★★ 5
It was worth every cent
Color: Cool Grey, Size: 24x24x12 inch
I have BPPV. It's a condition where tiny ear crystals come out of place and move within your ear canals - this fools your brain into thinking you're in motion, causing severe dizziness. The most common treatment is the Epley Maneuver, and that actually helps a lot. However, I was going through a period where every single day I'd wake up with severe dizziness. Even if I managed to do the Epley Maneuver and it worked, the entire rest of the day would be ruined because I'd still feel generally unwell and nauseous. I ended up getting a book about BPPV and the author strongly recommended sleeping at at least a 30 degree angle. So, that's why I ended up buying this wedge pillow...
I started using it April 26 and today is May 17. Since I began using it as a pillow, I have not woke up dizzy again. That is so huge! It may be that sleeping at a 30 degree angle deserves 5 Stars but thought I'd give this pillow 5 Stars too, as it's been a great experience. If you suffer from this, here's how the angle should be...If you lay your head on a pillow and open your eyes, you should not be looking at the ceiling. With the right angle, you should be looking at where the wall meets the ceiling. If so, you know you're at the right angle.
As far as pillow itself, I'd say the pillow case fabric is of average quality. Not really remarkable in any way. It seems decent. Good value for the price. The inside is firm (which is just what I needed) but comfortable, and I tend to not move around much the entire night. I like this very much and if it does start wearing out, I'll definitely come back here and buy another. Would recommend.
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Reviewed in the United States on May 17, 2023
★★★★★ 4
A bit too firm but great otherwise
Color: Cool Grey, Size: 24x24x12 inch
I got this wedge pillow primarily to have something to lean my head against (I like to lay on my side when reading or looking at my phone at night sometimes), or to sit upright when reading in bed. It's very comfortable doing both now. It does a really good job at being a nice support for the back of my bed. Only negative is I feel it's too firm. I wouldn't use it as a primary pillow, but it's definitely good for back support at least.
While I won't mark it down for this, I do find it very large. If you have anything smaller then a queen it may take up more of your bed then you'd like.
Definitely recommend. Hopefully will last quite a long while as well.
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Reviewed in the United States on April 11, 2025