Ronstan's award-winning Series 75mm Core Blocks have a tuned two-stage bearing system that provides excellent performance across the full working load range with an integrated thrust bearing feature and the resilience to handle dynamic or static loads.
Under moderate loads, the Acetal ball bearings ensure minimum friction. Under heavy loads, stage two kicks in and the sliding Acetal bearing on a polished stainless steel race takes over to maintain low-friction performance. Their alloy cheek plates have a flaring block throat and reduced gap between the cheek and the sheave to minimize rope wear.
The Series 75 Core Blocks are ideal for mainsheet, halyard, and spinnaker sheet applications on up to 46' (14m) and general applications on larger yachts. Alloy sheave models are available for use with wire.
This model's head assembly incorporates a brass bearing washer to provide smooth 360ﾰ rotation of the post and shackle. A set screw arrangement allows the head to be locked at 0ﾰ or 90ﾰ. Shackles are high-quality forged grade 316 stainless steel.
It's always a good idea to have spare RF618A, a 5/16 in pin diameter, standard Dee shackle with a coined pin head.
|Breaking Load (lbs)||6600|
|Breaking Load (kg)||1500|
|Clevis Pin (in)||5/16|
|Max Line Size (in)||9/16|
|Max Line Size (mm)||14|
|Safe Working Load (lbs)||3300|
|Safe Working Load (kg)||1500|
|Shackle Pin (in)||5/16|
|Shackle Pin (mm)||8|
|Sheave Diameter (in)||3|
|Sheave Diameter (mm)||75|