Ronstan Series 40 Single Stand-Up Orbit Block

The Ronstan Series 40 Single Stand-Up Orbit Block is a low-friction single block for deck installations where the sheave should remain presented to the line instead of falling flat. Its stand-up base allows useful articulation as the lead changes while keeping the block ready to accept the rope when the system is unloaded. Ronstan lists the Series 40 Orbit range for mainsheets and spinnaker sheets on dinghies, catamarans, and sportsboats, as well as halyard, vang, and backstay applications. The single-sheave format makes this model a versatile turning point rather than a dedicated multi-part purchase block.

The Orbit construction combines ball bearings for low running friction with a secondary full-contact bearing that supports the sheave under higher load. Toughened glass-fiber reinforced nylon cheeks replace heavier metal straps and help keep the block compact. The stand-up arrangement preserves movement at the base, allowing the block to follow modest changes in the working angle. Corrosion-resistant fittings and an open, serviceable shape make it suitable for equipment that sees regular saltwater exposure.

• Single-sheave stand-up Orbit configuration
• Two-stage bearing system for changing loads
• Lightweight glass-fiber reinforced cheeks
• Stand-up base maintains useful articulation

The block is sized for line up to 3/8 in, with an 880 lb maximum working load and a 1,760 lb breaking load. Ronstan lists the weight at about 2.5 oz, keeping moving weight low on dinghy and sportboat systems. Leave room around the base for articulation and make sure the rope enters the sheave without a hard side angle. For more stand-up Orbit blocks and small-boat rigging hardware, browse more Sailing Hardware.