The Ronstan Series 60 Core Block™ Single is a true all-round solution for sheets, halyards, and control line applications on cruising and racing yachts. A tuned 2-stage bearing system delivers class-leading performance across the full working load range — under moderate loads, acetal ball bearings ensure minimum friction; under heavy loads, a sliding acetal bearing on a polished stainless steel race takes over to maintain low friction. An integrated thrust bearing prevents the sheave from rubbing on the cheeks when the line lead isn't perfect.

The universal head provides full 3-axis articulation and can be locked at 0° or 90° using a 2.5mm hex key, or left free to swivel. The central hub doubles as a becket take-off or tie-up point for lines up to 11.5mm. Alloy cheek plates are cut-away for minimum weight and easy fresh water rinsing. An alloy sheave version for wire rope is also available.

Sheave: UV stabilised acetal (2-3/8" diameter)
Cheek Plates: Aluminium alloy, cut-away design
Ball Bearings: High compression strength carbon black acetal
Shackle, Post & Hub: Grade 316 stainless steel
Head: Universal, full 3-axis articulation — lockable at 0° or 90° (2.5mm hex key)
Hub: Becket take-off or tie-up point, max 11.5mm line
Max Rope Diameter: 1/2"
Pin Diameter: 1/4"
Max Working Load: 2,200 lb
Breaking Load: 4,410 lb
Weight: 8.3 oz
Item Code: RF64100