A turnbuckle, stretching screw or bottlescrew is a device for adjusting the tension or length of ropes, cables, tie rods, and other tensioning systems. It normally consists of two threaded eye bolts, one screwed into each end of a small metal frame, one with a conventional right-hand thread and the other with a left-hand thread. The tension can be adjusted by rotating the frame, which causes both eye bolts to be screwed in or out simultaneously, without twisting the eye bolts or attached cables.
I bought four stainless steel turnbuckles to replace the vernier adjusters on the shrouds of my sailboat.
The cotter pin diameter is 1/4" - the same as what I am replacing. I was told that that is the metric by which one judges the capability of a turnbuckle.
They have a 1 1/2" long thread on...