Series 30 Orbit Single Lashing Block with Self-Lubricating Nylatron® Sheave
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RONSTANSeries 30 Orbit Single Lashing Block with Self-Lubricating Nylatron® Sheave


In stock online.
Model # 10468551 | Mfg # RF35101DUPC # 9316800432981


Series 30 Orbit Single Lashing Block with Self-Lubricating Nylatron® Sheave

Name Value
Becket No Becket
Diameter 5/16 Inch or 8 mm
Direction Any
Integral Cleat No Integral Cleat
Mount Type Rope/Webbing
Ratchet Non Ratcheting
Safe Working Load 661 Pounds
Sheave Diameter 1 3/16 Inches or 30 mm
Type Single
Weight 0.7 Ounce

Product Overview

Lightweight and strong block made for rigging systems that use high-tech lines.

The 30mm single block is a true work horse and features a Nylatron® sheave with a V-profile for use with wire-rope. Ideal for halyards, outhauls, cascade system boom vang ans other applications that incorporate wire into the system.

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 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. With the reduction in weight also comes a smaller footprint right down to the cheeks separating the sheaves of double and triple blocks. The lower profile and compact size make these blocks ideal for applications such as barber haulers, spinnaker sheets, 2:1 jib sheet systems and more.

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 316 stainless steel bearing in the center. Conventional and high-tech lines run smoothly over the self-lubricating Nylatron® sheave.

Sailors can have their cake and eat it too Ronstan Orbit blocks. These compact bocks are ready to handle modern control line systems while providing smooth efficiency.

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
    • 316 stainless steel slide bearing supports higher static loads
  • Hollow bearing at center of sheave serves as a becket to reduce weight and offer additional versatility
  • Self-lubricating Nylatron® sheave designed to be compatible with wire and rope-wire rigging
  • Designed for lashing installations (accepts 4mm lashing)
  • Also available with stainless steel shackle or Dyneema link heads to meet the needs of different applications
  • Ideal for
    • Halyards
    • Cascade system boom vangs
    • Outhauls
    • 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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