[TowerTalk] Marine Pulleys

[Jim Lux]

On 9/11/11 7:03 PM, Grant Saviers wrote:
> Harken or Ronstan or Lewmar - all are top quality sailboat pulleys -
> called blocks.
>
> The ball bearing ones are really good since the friction is
> significantly reduced.
>
> Bigger is better for the pulley diameter, since there is less stress and
> fatigue on the rope, but they cost more as the size goes up as the Safe
> Working Load (SWL) also increases.  Two that I use are for 1/4"/8mm rope
> (line for sailors)
>
> Lewmar - 30mm PN 29901321 440# SWL stainless steel balls and swivel shackle
>
> Ronstan - 20 Series PN 20100 550# SWL SS balls&  swivel shackle
>
> Both were about $17 last time purchased and are stocked by West Marine
> and many others.
>

Also, bear in mind that these things are designed for a particular 
diameter line (rope).  The groove in the sheave is sized for what is 
passing through it.