Series 40 All-Purpose Single Block

General application plain-bearing blocks provide performance and value.

A smooth and efficient block is critical to the conversation between sailor and boat—especially for handheld control lines. Ronstan designed the Series 40 All-Purpose blocks to give dinghy and small keelboat sailors the feedback to detect subtle wind changes and sail as efficiently as possible.

These lightweight blocks feature a durable, self-lubricating, UV stable acetal sheave that runs smoothly on a Grade 316 stainless steel shaft. Fiber reinforced nylon cheeks provide rigidity and strength and are beefed up with 316 stainless steel load straps. The included shackle features a screw pin with a low-profile head to prevent snagging on smaller lines. Get the messages your boat sends you though the lines by using efficient and smooth Ronstan Series 40 All-Purpose blocks.

This 40mm single with shackle head is versatile and can be used for a wide range of applications. Great for halyard tuners, Cunninghams, dinghy sheets and more. 

Key Features

• Lightweight blocks designed for moderate to high static and dynamic loads
• Ideal for handheld control lines
• Captive lock secures swivel at  0° or 90° or left to swivel freely
• Sliding acetal plain bearing on 316 stainless steel shaft handles high loads and maintains low friction
• Fiber reinforced nylon cheeks to add strength while reducing weight
• Self-lubricating, UV stable acetal sheave is strong and lightweight
• Grade 316 stainless steel load straps add strength
• Ideal for: Dinghy and small keelboat sheets, halyard tuning systems, backstay systems on dinghies and smaller keelboats, boom vangs (cascade systems)