Ronstan Core Block Range
Ronstan invested significant time and effort in developing this functional and stylish range, for keelboat sailors.
Core Blocks come in three standard sizes:
Core 45 – Max rope diameter 12 mm, Boats up to 33ft*
Core 60 – Max rope diameter 12 mm, Boats up to 36ft*
Core 75 – Max rope diameter 14 mm, Boats up to 46ft*
* Ideal for mainsheet, halyard and Spinnaker sheet applications but also suitable for various control lines on larger yachts.
Designed to be robust, durable and provide trouble-free performance, the range has the following features:
• Two-Stage Universal Bearing system - For low to moderate loads, the acetal ball
bearings are used. For higher loads where these bearings can deform, a sliding acetal
plain bearing on a polished stainless-steel race takes over. This results in low friction
through the full load range.
• Aluminum cheeks – High quality, hard anodized aluminum with a low-weight, cut-
• Universal swiveling head with brass bearing washer provides smooth 360° rotation of
the post and shackle
• The hallow hub has been specially designed with flared edges, to allow it to be used
as a becket.