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Exploring Karver KBO Block options

by Phil Anniss 28 Jan 09:00 UTC
Exploring the Karver KBO Block Range © Karver

Karver are renowned for manufacturing simple, reliable and high-performance sailing solutions, often utilising user-feedback from sailors in the design process to create products that emphasise innovation and ease of use. Consequently, it's no surprise that Karver hardware is a favourite on high-tech racing yachts, plus on the decks of ambitious cruisers too.

The Karver KBO Block range is no different. A mainstream range of lashing blocks, the KBOs are extremely versatile and adaptable, with a wide range of single, double and triple blocks suitable for applications up to a max line diameter of 18mm (5T SWL). Due to the block's popularity, additional models have since been introduced: the KBO foot block, the KBOW reversible ratchet block and the KBOJ jammer block.


Karver KBO blocks reduce weight and friction whilst increasing strength and ease of use. In part, this is due to the rope lashing which - when compared to a steel shackle - is not only lighter, but faster and easier to install, plus will not corrode or seize up due to load or rust.

From KBO4 up, the blocks use low friction roller bearing technology inspired by the Karver KBTi. Additionally, attachment through the centre increases the blocks safety by ensuring the working line will always be connected to the rope lashing - even in the unlikely scenario the block was to fail under extreme load.


A multi-purpose lashing block with composite cheeks (plastic and fibre) and high-performance polymer central roller bearings available as a single, double or triple block. Perfect for building cascade systems. Available models: KB01, KB02, KB04, KB06 and KB08.

  • Range - Single: 6mm, 0.15T SWL - 12mm, 0.85T SWL
  • Range - Double: 6mm, 0.25T SWL - 12mm, 1.3T SWL
  • Range - Triple: 6mm, 0.35T SWL - 12mm, 1.8T SWL

KBO10 - KBO50:

For greater load requirements, these blocks replace composite cheeks with aluminium alloy and utilise a two stage bearing system to enhance low friction performance. Lashing guide supplied. These are only available as a single block. Available models: KBO10, KB015, KB020, KBO30, KB050 (Rope shackle not supplied for KBO50)

  • Range: 12mm, 1.2T SWL - 18mm, 5T SWL


Utilising composite plastic and fibre cheeks, the reversible ratchet can work in either direction so the line can pass through both ways. There are 30 lock positions on the sheave inside the diameter to ensure precise sheet control. Available models: KBOW

  • Range: 10mm, 0.3T SWL


A triple KBO6T (triple) lashing block with an attached KJ3 jammer, which can be combined with a additional, standard KBO6T for a lightweight, stand-alone 6:1 purchase system. Available models: KBO6TJ

  • Range: 10mm, 0.8T SWL

KBO Foot Blocks:

Karver KBO blocks adapted for bolting onto the deck. Available models: KBO2 - KBO30

  • Range: 8mm, 0.22T SWL - 16mm, 3.5T SWL


The Karver KBO range is a series of solid, reliable and popular blocks, perfect for a range of sailing applications due to the soft connection which makes them adaptable and flexible to use.

You can view the Karver KBO block range at

If you have any questions about any deck hardware issues feel free to contact or use the Deck Hardware Enquiry Form.

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