Ronstan Series 40 Ratchet Orbit Block - Single - Auto - Swivel Shackle Head

The Series 40 Ratchet Orbit Block™ is engineered for superior performance in marine and boating applications. Designed with advanced features such as an automatic ratchet mechanism and high holding power, this versatile block ensures smooth sail handling and reliable control in various sailing conditions.

Automatic Ratchet Mechanism

The automatic ratchet system engages seamlessly when load is applied and disengages upon release. This feature allows the sheet to run out smoothly and freely, making it ideal for rapid easing of sheets and gybing asymmetric spinnakers with ease.

Unmatched Holding Power

Ronstan Ratchet Orbit Blocks™ offer the highest holding power available in the market. Featuring a sophisticated NC-machined sheave with Generation 2 sheave cross-hole geometry, the Series 40 delivers up to 14:1 holding power—nearly double that of the closest competitor.

Advanced Sheave Design

The unique sheave design incorporates eight gripping faces that directly resist loaded line movement. Unlike traditional designs with angled resistance, our Generation 2 sheave features straight resistance faces that distribute the load evenly and minimize rope wear. These faces are offset from the radial line, effectively drawing the rope into the gripping area under load.

Easy and Secure Attachment

The Dyneema® Link ensures a hassle-free installation, securely retained by a molded retainer clip. This flexible link can remain attached to the block during fitting, eliminating the risk of losing shackle pins. Additionally, the system is compatible with Dyneema®/Spectra® strops, webbing, and carbon connection points, offering greater versatility compared to traditional steel loop tops or shackles.

Smooth Sheet Easing

With automatic models, the sheet disengages smoothly as soon as the ratchet mechanism releases. This ensures effortless and controlled easing of sheets, enhancing overall sail management.

Low Profile Stand-Up Kit

The low profile stand-up kit includes a clatter-free rubber boot and allows for 0° or 90° alignment. You can attach the Dyneema® link either aligned with the stand-up base or across it, providing a neat solution that permits full articulation without adding bulk.

Key Features

• 14:1 Holding Power: Highest holding power available for reliable performance.
• Smooth Easing: Effortless and controlled sheet management.
• Automatic Ratchet Engagement: Fully automatic load sensing for seamless operation.
• Swivel Shackle Head: Enables unlimited block rotation for versatile rigging options.
• Stainless Steel Shackle: Ultimate durability and compatibility with harsh marine environments.

Ideal Applications

• Dinghy mainsheet systems
• Mainsheet fine-tuning systems on sportsboats and small keelboats
• Mainsheet systems on sportsboats using RF7 mainsheet swivel cleat units
• Spinnaker and job sheets on dinghies, especially modern asymmetric classes
• Control line applications on larger yachts

Premium Materials

• Sheave: Hard anodized Aluminium for durability
• Ball Bearings: High compression strength carbon black Acetal
• Frame/Cheeks: Toughened, glass fiber reinforced Nylon
• Rope Link: UV stabilized, multi-strand impregnated SK75 Dyneema® for superior strength

Specifications

Specification	Details
Sheave Ø	40mm (1-9/16")
Max. Rope Ø	9mm (5/16")
Maximum Working Load (M.W.L.)	175kg (385lbs)
Breaking Load (B.L.)	500kg (1,100lbs)
Weight	44g (1.5oz)

Orders of physical products placed by 3 PM EST M-F typically ships the same day, if all requested items are in stock. Weekend orders will typically ship on Monday.

Shipping takes 2-7 days.

We currently ship to the Contiguous 48 States.

Life of Sailing merch is custom made for the customer after an order is placed. Total turnaround is typically 7-14 days from order to doorstep.