The Ronstan RF185 Series 30 Single Utility Block is a lightweight, durable, and versatile sailing pulley designed for efficient line handling across a wide range of marine applications. Featuring a 30mm single sheave and tube rivet head, this block is ideal for simple control systems where reliability and ease of installation are essential.

Constructed with UV-stabilised acetal sheaves and corrosion-resistant stainless steel cheeks, the RF185 ensures smooth, low-friction performance and long service life in New Zealand’s harsh saltwater conditions. Its tube rivet head design allows flexible attachment using screws, shackles, or lashings, and can also be used as a becket for additional purchase.

Perfect for dinghies, trailer yachts, and small keelboats, the RF185 is widely used in vang, cunningham, trapeze retriever systems, and general control line setups, as well as leech line tackles on larger yachts.

Key Features

• 30mm single sheave for smooth, efficient line control
• Durable stainless steel cheeks for corrosion resistance
• UV-stabilised acetal sheave for low-friction performance
• Tube rivet head allows versatile mounting or becket use
• Lightweight, maintenance-free construction
• Ideal for vang, cunningham, and control line systems
• Trusted Ronstan Series 30 marine hardware

Specifications

• Sheave Diameter: 30mm
• Max Rope Diameter: 8mm
• Maximum Working Load: 300kg
• Breaking Load: 900kg
• Weight: Approx. 20g
• Construction: Stainless steel cheeks, acetal sheave

Why Choose the Ronstan RF185? 

For New Zealand sailors, simplicity and durability are key in rigging hardware. The RF185 provides a cost-effective, reliable single block solution for a wide range of onboard applications.

Its compact size, corrosion-resistant materials, and versatile attachment design make it an essential component for both recreational sailing and performance setups in coastal and offshore environments.