Single Blocks

Low-friction Carbo Air blocks are lightweight, strong, reliable—and affordable. Companions to the popular Harken Black Magic block line, these small, compact blocks have very high working loads for safe, easy trimming. Sheave: 57 mm / 2 1/4 in...

The Ronstan 15 mm Utility Block range offers small boat sailors a lightweight, stainless steel block range for a variety of applications such as control lines and shockcord tension systems. This is the basic loop head type single block, great for lashing...

The 16 mm is Harken’s smallest block. It is perfect for small synthetic control lines found on high-tech dinghies. The patented bearing system uses stainless steel balls in a captive grooved race and has a 250 lb (113 kg) maximum working load. ...

Ronstan's ball bearing blocks were conceived and engineered for the demands of competitive sailing in all types of boats and have rapidly become the international choice for high performance hardware. Highly efficient, low friction bearing systems for...

Low-friction Micro blocks are compact and lightweight. They are ideal for sailboards, smaller dinghies, and lightly loaded control lines on boats of all sizes. Sheave: 22 mm / 7/8 in Length: 51 mm / 2 in Weight: 21 g / .75 oz Maximum line: 6 mm / 1/4 in...

Low-friction Carbo blocks are lightweight, strong, reliable—and affordable. Companions to the popular Harken Black Magic block line, these small, compact blocks have very high working loads for safe, easy trimming. Sheave: 29 mm / 1 1/8 in Length:...

Low-friction Bullet blocks lead control lines aft. They are compact and lightweight, with fast trim and release under high or low loads. A range of styles lets these blocks adapt to almost all control line applications. Sheave: 29 mm / 1 1/8 in Length:...

Low-friction Bullet blocks lead control lines aft. They are compact and lightweight, with fast trim and release under high or low loads. A range of styles lets these blocks adapt to almost all control line applications. Wire Bullet blocks use roller...

Low-friction Bullet blocks lead control lines aft. They are compact and lightweight, with fast trim and release under high or low loads. A range of styles lets these blocks adapt to almost all control line applications. Sheave: 38 mm / 1 1/2 in Length:...

Low-friction Carbo Air blocks are lightweight, strong, reliable—and affordable. Companions to the popular Harken Black Magic block line, these small, compact blocks have very high working loads for safe, easy trimming. Sheave: 40 mm / 1 9/16 in...

40mm single block with becket from the Ronstan All Purpose (AP) blocks range, a great all around solution for a variety of rigging applications. Self-lubricating Acetal polymer sheaves running on polished stainless steel races perform equally well with...

Low-friction Carbo Air blocks are lightweight, strong, reliable—and affordable. Companions to the popular Harken Black Magic block line, these small, compact blocks have very high working loads for safe, easy trimming. Sheave: 57 mm / 2 1/4 in...