Ronstan Marine Series 25 Ball Bearing HHL Lashing Orbit Block™ RF28109HL

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.

Specifications

• Brand: Ronstan Marine Inc.
• Manufacturer part number: RF28109HL
• UPC: 9316800661930
• Shipping weight: 0.02 lb