2025 Ronstan Marine Catalogue - Catalog - Page 72
FEATURES & INFORMATION
Soft Attachment SNATCH Blocks
70
Primary bearing
Thrust washer
SA block sheave
Cheek plates rotate to open block
Self-lubricating composite
journal bearing
Soft shackle & aluminium dog bone
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SA SNATCH BLOCKS
SOFT ATTACHMENT BLOCKS
Designed from the outset to deliver outstanding performance, these blocks
achieve the highest ratings for dynamic load vs sheave diameter in our
keelboat block range. They are built to perform and built to last. Every SA
Snatch Block features fully machined, anodised aluminium cheek plates.
Sheaves run on duplex stainless steel hubs and incorporate precision
composite journal bearings and thrust washers. The soft attachment is a
purpose designed Dyneema® SK99 cord shackle with aluminium dog bone.
Ultimate dynamic and static load performance
SA Snatch Blocks incorporate a full contact, self-lubricating composite journal bearing
running on a polished duplex stainless steel hub, to maintain low friction performance
under heavy dynamic and static loads.
Thrust washers in the same composite material are positioned between the sheave
and the cheek plates to handle the high side loads that can be generated when line
entry and exit alignment is not ideal. Testing has shown reduced friction and greater
durability than ball bearings in this application.
Attach, detach and open
The soft shackle provides a simple means of attachment, secured with the aluminium
dog bone but easily opened when necessary to detach the block.
With the shackle open a gentle rotation of the cheek plates opens the head of the
block so it can be 昀椀tted to a standing line. To close the block, rotate the cheeks back
to the closed position until the spring loaded ball lock secures them in place. No
additional external straps or bands required.
Soft shackle with aluminium dog bone
Drawing on the expertise of Nodus Factory, many design iterations were tested before
昀椀nalising speci昀椀cations of the Dyneema® SK99 cord shackle and aluminium dog bone.
Proprietary Nodus Factory splicing techniques and 昀椀bre surface coating ensure secure
load transfer from the block and maximum durability.
Aluminium alloy cheek plates & sheaves
Block cheeks and sheaves are precision machined from high strength aluminium alloy,
anodised for durability and corrosion resistance. The soft attachment through the hub
provides a protective bu昀昀er between the block and boat surfaces. Retaining guides in
soft elastomer ensure that the block remains aligned within the soft shackle.
A multitude of applications
Suited to temporary or permanent line de昀氀ection, load carrying and snatch block
applications including: 2:1 main halyards, headsail and spinnaker sheets, mast base
halyard de昀氀ection, and running backstays.
