Collection: Blocks

Blocks redirect running rigging and control lines across virtually every point on a sailboat, and the differences between them matter more than most buyers expect. Sheave diameter is the first thing to match: a 25mm Nylatron sheave suits light wire and smaller diameter lines, while a 45mm or 66mm race sheave handles heavier loads with less friction. Bearing type is the other major split. Acetal solid-bearing sheaves from Ronstan offer durability and low maintenance for cruising use, while ball-bearing blocks like the Ronstan Series 30 or Harken Carbo T2 reduce friction noticeably under load, making them the choice for racing applications where line control is critical.

Attachment style is equally important before you buy. Wire blocks from Ronstan come with tubular rivet heads, removable clevis pins, or ferrule tops, each suited to different deck fittings and rigging setups. T-track orbit blocks require a compatible track already installed. Barton Marine and Harken round out the selection with their own hardware standards, so confirm compatibility with your existing tracks and fittings. Ronstan kite blocks serve spinnaker and asymmetric kite sheets specifically. Match the block to the line diameter, the load, and the attachment point before ordering.