Allen 40mm Triple Block with Swivel Head

The Allen 40mm Triple Block with Swivel Head is a high-performance sailing block designed for strength, efficiency, and smooth operation in demanding dinghy and keelboat rigging systems. Manufactured from high-strength, lightweight glass-filled nylon, it delivers exceptional durability while maintaining a low overall weight for performance sailing applications.

At the core of its design is Allen’s dynamic bearing technology, featuring twin rows of stainless steel ball bearings running on a precision stainless steel rail. The caged bearing system reduces friction, improves load distribution, and significantly enhances longevity compared to conventional block designs. This makes it ideal for high-load control lines where reliability and smooth trimming are essential.

The integrated 360-degree swivel head includes a 4mm high-strength shackle, rated above the block’s load capacity for added safety and performance confidence. Despite its compact size, the shackle is engineered for demanding sailing loads and ensures secure, efficient rigging alignment.

Designed for versatility, this 40mm triple block is ideal for mainsheets, jib sheets, spinnaker sheets, and a wide range of keelboat and dinghy control line systems.

Key Features

• High-performance 40mm triple block with swivel head
• Lightweight, high-strength glass-filled nylon construction
• Allen dynamic bearing system with twin stainless steel ball races
• Caged ball bearings for reduced friction and improved efficiency
• 360-degree swivel head for optimal load alignment
• High-load rated 4mm shackle for secure rigging
• Designed for dinghy and keelboat performance sailing
• Smooth operation under high load conditions

Applications

• Main sheet systems
• Jib sheet systems
• Spinnaker sheets
• Control line systems
• Dinghy and keelboat rigging setups

Specifications

• Part Number: AL-20403
• Length: 92mm
• Maximum Line Diameter: 10mm
• Shackle Pin Diameter: 5mm
• Breaking Load: 1400kg
• Maximum Working Load: 750kg

The Allen 40mm Triple Block with Swivel Head delivers outstanding strength, low friction performance, and dependable durability for modern high-load sailing systems.