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

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    Sale Price $153.85 Regular Price $181.00
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    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)

    Product Specifications
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    Documents
    User Manual Download
    Specification Sheet Download
    Safety Guide Download
    Service & Support

    Warranty

    This product is backed by a 12-month limited warranty, covering defects in materials and workmanship under normal use.

    Technical Assistance

    Our dedicated support team is available to assist with product setup, operation guidance, and troubleshooting. Contact us via email or phone for prompt service.

    Documentation & Downloads

    Access essential resources including the user manual, technical specifications, and safety instructions in our online support center.

    Replacement Parts & Accessories

    We offer a full range of genuine replacement parts, including batteries, chargers, and compatible accessories to ensure long-term performance.

    Training & Tutorials

    Browse our library of how-to videos and maintenance tips to get the most out of your cordless drill.

    FAQs

    Find quick answers to common questions

    Product & Usage

    1. Are KRANK tools built for professional use?

    Yes, all our tools are engineered for heavy-duty performance and long-term reliability.

    2. Are KRANK tools safe to use for beginners?

    Yes, our tools are designed with safety features and easy handling in mind.

    3. Can KRANK tools be used in extreme conditions?

    Yes, they are tested to perform reliably in demanding environments.

    Maintenance & Accessories

    1. What maintenance is required for the tools?

    Regular cleaning and proper storage are usually enough to keep your tools in top condition.

    2. Can replacement parts or accessories be purchased separately?

    Yes, we provide compatible parts and add-ons to extend the life of your tools.

    3. Do you provide instruction manuals or usage guides?

    Every tool comes with a detailed user manual, and digital guides are available online.

    Warranty & Guarantee

    1. Do the tools come with a warranty?

    Every KRANK tool includes a 1-year warranty, with extended options available on select products.

    2. How do I register my KRANK tool for warranty coverage?

    You can register online using your product serial number for faster support.

    3. What does the warranty cover?

    It includes defects in materials and workmanship under normal use conditions.

    4. Is there an option to extend the warranty?

    Yes, extended warranty plans are available for select tools at checkout.

    Purchasing & Support

    1. How fast is shipping and delivery?

    Orders ship within 24 hours, and delivery typically takes 3–5 business days.

    2. Do you offer bulk or corporate purchasing options?

    Yes, KRANK provides special pricing and packages for business or team orders.

    3. How can I contact customer support if I need help?

    You can reach our support team by email or phone — we’re here to assist you.

    Can’t find your answer?

    Feel free to reach out to us!

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