Ronstan Series 40 Fiddle Becket Cleat Block

The Ronstan Series 40 Fiddle Becket Cleat Block combines a fiddle layout, removable becket, and adjustable cleat for compact purchase systems. That combination works especially well in mainsheet and boom-vang tackles, where the standing end and working end can remain organized around one block. The Captive Lock head can be fixed in either of two planes or left free to swivel, letting the block match the geometry of the rig. Ronstan also lists the configuration for halyard and control-line systems, including fine-tune mainsheet tackles, cunninghams, and backstays.

The Series 40 all-purpose bearing arrangement uses self-lubricating Acetal sheaves running on polished stainless races, a combination chosen for low maintenance and steady performance under both moving and static loads. Fiber-reinforced nylon cheeks keep the fiddle block light while Grade 316 stainless hardware carries the primary load path. The Captive Lock head can be fixed in either of two planes or left free to swivel, so the block can be matched to the geometry of the purchase. Its becket pin is removable, letting a line be spliced before final assembly instead of forcing the splice around installed hardware.

• Exceptionally high working loads
• Low maintenance, long service life
• Self-lubricating sheave
• Captive Lock universal head

Choose the line diameter and attachment hardware as part of the complete fiddle purchase rather than sizing the block in isolation. The Captive Lock head should be set to the plane that lets the tackle align naturally, and the removable becket pin should be secured after any splice is completed. Set the cleat-arm angle from the crew's normal working position so the line can be released without a sharp sideways pull. For more fiddle blocks, cleats, and compact purchase hardware, browse more Sailing Hardware.