Series 30 Orbit Single Block with Swivel for use with Wire
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RONSTANSeries 30 Orbit Single Block with Swivel for use with Wire


In stock online.
Model # 10468528 | Mfg # RF35100DUPC # 9316800432998


Series 30 Orbit Single Block with Swivel for use with Wire

Name Value
Becket No Becket
Diameter 5/16 Inch or 8 mm
Direction Any
Integral Cleat No Integral Cleat
Mount Type Swivel Shackle
Ratchet Non Ratcheting
Safe Working Load 661 Pounds
Sheave Diameter 1 3/16 Inches or 30 mm
Type Single
Weight 1.1 Ounces

Product Overview

Lightweight and strong blocks with a sheave to handle wire or rope.

Ronstan’s goal for the Orbit Blocks™ was to produce a block with the highest strength to weight ratio—and they nailed it. Through extensive computer modeling unnecessary metal components were replaced by engineered light-weight composites without compromising strength. The unique glass fiber reinforced nylon cheeks and head are designed to accept Dyneema® links or high-tech lashing and eliminate the need for heavy shackle pin posts and metal load frames. The hollow bearing at the center of the sheave serves as a becket to further reduce weight.

Performance is not lost with the weight savings. In fact the Orbit Blocks™ have the highest working loads in their class and feature an improved two-stage bearing system that efficiently handles static and dynamic forces throughout the load range. High compression grade acetal orbital ball bearings migrate to the loaded area of the sheave to handle light to moderate loads; larger loads are shouldered by the full-contact PTFE impregnated nylon bearing with carbon fiber reinforcement. Conventional and high-tech lines run smoothly over the UV resistant acetal sheave

Sailors can have their cake and eat it too with Ronstan Orbit Blocks™. These lightweight and compact bocks are smooth, efficient and are an ideal solution for modern control line systems.

The 30mm single block with becket and swivel is a true work horse. This block features a Nylatron® sheave that is compatible with wire-rope applications making it ideal for wire-rope halyards, trapeze systems, backstay systems and other control lines that use both wire and rope.

Key Features

  • Excellent strength to weight ratio
  • Improved two-stage bearing system for efficiency for static and dynamic loads
    • Acetal ball bearings migrate to load areas of the sheave for light to moderate loads
    • PTFE impregnated nylon bearing with carbon fiber reinforcement supports higher static loads
  • Hollow bearing at center of sheave serves as a becket to reduce weight and offer additional versatility
  • Nylatron® sheave features a V-groove for use with wire-rope and can be used with conventional doublebraid and high-tech 12 stand lines
  • Available with stainless steel shackle or Dyneema link heads to meet the needs of different applications
  • Includes swivel head with shackle
  • Ideal for
    • Wire-rope halyards
    • Backstay systems
    • Trapeze systems
    • General dinghy control lines that use both wire and rope

Orbit Blocks™ User Instructions

Ronstan Orbit Blocks™ Selection Guide

Sheave DiameterLine CompatibilityShackle Pin Diameter (if applicable)
20mm1/4" (6mm)1/8"
30mm5/16" (8mm)5/32"
40mm5/16" (9mm)5/32"
50mm3/8" (10mm)3/16"
55mm3/8" (10mm)3/16"
70mm1/2" (12mm)Only available with Dyneema® link


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