Ronstan RF51200 Series 50 Double Block with Swivel Shackle Head

The Ronstan Series 50 All Purpose Double Block delivers exceptional performance for cruising and racing sailboats up to 33 feet. This versatile marine block features self-lubricating Acetal polymer sheaves running on polished stainless steel races, providing smooth operation under both dynamic and high static loads. The swivel shackle head allows full 360-degree rotation for optimal line management.

Key Features:

• Double sheave configuration with 2-inch (50mm) diameter sheaves
• Exceptionally high working load of 2,200 lbs (1,000 kg) with 4,410 lb breaking strength
• Self-lubricating Acetal polymer sheaves ensure low friction and extreme durability
• Slotted pin shackle design eliminates fouled lines
• Non-locking swivel head provides 360-degree rotation
• Low maintenance design for long service life

Construction:

• Grade 316 stainless steel load strap for superior corrosion resistance
• Impact and UV resistant fiber-reinforced Nylon cheeks
• Polished stainless steel races for smooth sheave operation
• 1/4-inch (6mm) pin diameter

Applications:

• Mainsheet and halyard systems
• Vang and spinnaker control lines
• General sheet and control line applications on boats up to 33 feet (10m)

Specifications:

• Maximum rope diameter: 1/2 inch (12mm)
• Weight: 9.0 oz (255g)
• Maximum working load: 2,200 lbs (1,000 kg)
• Breaking load: 4,410 lbs (2,000 kg)

Ideal for sailors demanding reliable, high-performance blocks for their control line systems, the Ronstan RF51200 combines durability with smooth, low-friction operation.