57MM SINGLE BLACK MAGIC AIR ALUMINUM BLOCK W/SWIVEL

Harken 57mm Black Magic Aluminum Block with Swivel

The Harken 57mm Black Magic Aluminum Block with Swivel is a high-load, smooth-running pulley built for demanding rigging applications where strength and low-friction performance matter. With a 57mm aluminum sheave, this block offers a major step up in load capacity compared to lighter Carbo-style blocks, while still keeping a compact profile.

The swivel head helps the block align naturally under load, reducing line twist and keeping your rigging running clean. It’s a strong option for heavier outrigger rigging, dredge pulley setups, teaser systems, halyard-style applications, and custom marine rigging where durability and smooth line movement are key.

Key Features

• Single 57mm aluminum sheave design
• Swivel head for cleaner line alignment
• Black Magic aluminum construction
• High-load design for demanding rigging applications
• Smooth-running bearing system
• Compact size with serious strength
• Works with line up to 7/16"
• Great for custom rigging, dredge setups, teaser systems, outrigger rigging, and marine tackle applications
• Manufacturer part number: 3215

Specs

• Sheave: 57mm / 2-1/4"
• Length: 119mm / 4-11/16"
• Weight: 5.36 oz / 152g
• Shackle Pin: 1/4" / 6mm
• Max Line Diameter: 7/16" / 12mm
• Max Working Load: 2,500 lb / 1,134kg
• Breaking Load: 5,000 lb / 2,268kg

The Harken 57mm Black Magic Aluminum Block is a heavy-duty choice for crews who need compact size, smooth operation, and serious load capacity in one clean rigging package.