Used for internal halyards on the Catalina 22, Capri 22, and Catalina 25. Our replacement blocks are fabricated with aluminum sheaves in place of the original plastic sheaves.
These are perfectly sized for use with 1/4" line. Catalina Yachts uses them for 5/16" line also. When used with 5/16" the line does touch the smooth frame on either side a bit. Not enough to cause a problem, but still it does touch. The advantage is, the blocks only require a narrow slot in the mast, much smaller than a Harken exit block for example.
Mounting hole size:
Fastener hole spacing center to center:
Fastener hole size:
Overall size at mounting flange:
Note: In the photo above, the block is oriented as required for use at the base of the mast of the Catalina 22 and Catalina 25. The main and jib halyards exit below the sheave. When installed as the spinnaker or jib halyard block at the top of the mast on a Capri 22, it is installed with the sheave near the bottom of the block with the line exiting above the sheave.