Ronstan Series 60 Core Block™ - Single

The Ronstan Series 60 Core Block – Single is a precision sailing and rigging hardware component designed for demanding marine and performance applications where load transfer and durability are non-negotiable. Built by Ronstan, a trusted leader in high-performance marine hardware, this single block serves as the backbone for mainsheet systems, boom vang setups, and other critical rigging configurations on racing yachts and performance cruisers. Whether you're upgrading an aging racing rig or building a new system from scratch, this core block delivers the reliability and efficiency that serious sailors depend on.

At the heart of this block is Ronstan's tuned 2-stage bearing system, engineered to provide smooth, efficient performance across the full working load range without compromising under shock loading or sustained stress. The integrated thrust bearing feature eliminates lateral movement and distributes force evenly, reducing wear on sheaves and lines while maximizing mechanical advantage in your rigging system. The compact footprint—measuring just 4 x 2 x 7 inches and weighing only 0.6 pounds—makes it ideal for tight spaces on deck while maintaining exceptional strength-to-weight ratio, a critical consideration for any weight-conscious rig.

This single block is best suited for sailors running high-performance mainsheet or vang systems who need predictable load handling without maintenance delays or performance fade. The resilient bearing design handles both static loads (from steady-state sailing) and dynamic loads (from sudden direction changes or gust response) with equal proficiency, making it equally at home on a race course or extended cruising passage. Compatibility with standard Ronstan hardware makes integration into existing systems straightforward, and the proven design ensures that your investment will deliver years of reliable, silent operation.