DESCRIPTION

Series 25 Ball Bearing HHL Lashing Orbit Block™

Single sheave ball bearing high load block with becket hub option and lashing head.

The Series 25 Ball Bearing Orbit Blocks™ deliver superior strength, reduced weight, and exceptional performance for high-demand dinghy and small boat applications.

Designed with competitive sailors and performance boats in mind, these compact 25mm blocks are engineered to achieve the highest possible strength-to-weight ratio. Featuring Ronstan’s renowned high-compression strength acetal bearing system, the Series 25 BB Orbit Blocks are a lightweight yet durable solution, ideal for control line systems such as mainsheet and spinnaker sheet turning blocks, cunninghams, and cascading vangs on dinghies up to 4 metres.

Each block has a stainless steel hub for versatile lashing attachments and through-sheave becket functionality, making them adaptable to a wide range of rigging setups. The hub accommodates up to 4mm (5/32") lashing and ensures maximum efficiency without compromising reliability.

The range also includes a High Load (HHL) variant – the RF28109HL – which is equipped with a Grade 2205 stainless steel sheave and bearing race, paired with Grade 304 stainless steel ball bearings. These HHL blocks are purpose-built for high-load applications and are increasingly in demand for modern performance and foiling boats using small-diameter lines to carry significant loads.

Features:

  • 2-stage ball bearing system.
  • Suits up to 8mm (5/16”) lines.
  • Hollow hub for becket take-off.
  • Lashing blocks suit up to 4mm (5/32”) lashing.

Specifications:

  • Max. Rope diameter (in): 5/16
  • M.W.L. (lb): 880
  • Sheave diameter (in): 1
  • B.L. (lb): 2650
  • Weight (oz): 1.2

Applications:

  • Mainsheet and spinnaker sheet turning blocks on dinghies to 4m (13ft). 
  • Control lines.
  • Cascading vangs.
  • Leech lines & cunninghams.

Materials:

  • Frame/cheeks: Toughened, glass fibre reinforced nylon.  
  • HHL Sheave and bearing race: Grade 2205 stainless steel with Grade 304 stainless steel ball bearings.

Our Part # RONRF28109HL | Mfr. Part # RF28109HL

FEATURES

  • 2-stage ball bearing system.
  • Suits up to 8mm (5/16”) lines.
  • Hollow hub for becket take-off.
  • Lashing blocks suit up to 4mm (5/32”) lashing.

TECHNICAL INFORMATION

SpecificationValue
ManufacturerRonstan
Manufacturer part numberRF28109HL
Max. Rope diameter (in)5/16
M.W.L. (lb)880
Sheave diameter (in)1
B.L. (lb)2650
Weight (oz)1.2
Frame/cheeksToughened, glass fibre reinforced nylon.
HHL Sheave and bearing raceGrade 2205 stainless steel with Grade 304 stainless steel ball bearings.
Supplier technical detailDesigned with competitive sailors and performance boats in mind, these compact 25mm blocks are engineered to achieve the highest possible strength-to-weight ratio.
Supplier technical detailEach block has a stainless steel hub for versatile lashing attachments and through-sheave becket functionality, making them adaptable to a wide range of rigging setups.
Supplier technical detailThe hub accommodates up to 4mm (5/32") lashing and ensures maximum efficiency without compromising reliability.
Supplier technical detailThe range also includes a High Load (HHL) variant – the RF28109HL – which is equipped with a Grade 2205 stainless steel sheave and bearing race, paired with Grade 304 stainless steel ball bearings.
Supplier technical detailSuits up to 8mm (5/16”) lines.
Supplier technical detailLashing blocks suit up to 4mm (5/32”) lashing.
Supplier technical detailMainsheet and spinnaker sheet turning blocks on dinghies to 4m (13ft).
Supplier material detailHHL Sheave and bearing race: Grade 2205 stainless steel with Grade 304 stainless steel ball bearings.
ApplicationsMainsheet and spinnaker sheet turning blocks on dinghies to 4m (13ft). Control lines. Cascading vangs. Leech lines & cunninghams.
MaterialsFrame/cheeks: Toughened, glass fibre reinforced nylon. HHL Sheave and bearing race: Grade 2205 stainless steel with Grade 304 stainless steel ball bearings.