Holes and pin diameters should match - yes?

[oomfh]

Had a new forestay made for a new furler. Provided the rigger with all necessary dimensions including pin diameters. The hole diameter in the upper toggle he installed is larger than the masthead pin.

Humor me a moment with this question, when it come to sailboat rigging - shouldn't hole and pin diameters always match?

[amarinesurveyor]

Yes. If the pin is smaller diameter than the hole in the stay, it is a point load and will eventually start to elongate the hole.
Brian

[knothead]

Originally Posted by oomfh

Humor me a moment with this question, when it come to sailboat rigging - shouldn't hole and pin diameters always match?

In my opinion yes. Typically a hole is about 1/64" larger than the pin.
However, when I asked a Selden representative about this recently, I was told that they commonly will use a 14mm pin in a 16mm hole and they considered this appropriate.
I disagree but I'm in no position to argue.

[SVPrairieRose]

Would not be hard to use a bushing, except it is way up there!

[oomfh]

Got on the McMaster Carr website to look for a bushing, 3/8" OD, 5/16" ID and they have it, in three different grades of bronze! Unbelievable!

Fortunately we haven't raised the mast for this sailing season yet.

Thank you for all of the valuable input. "Load point" is the exact term I was looking for.

[SVPrairieRose]

Enjoy the season!

[DonScribner]

You (we) really need to fix that. (Mine is at the lower end). Think of it this way. I'll simplify and exaggerate. It it's 2" around the pin, then 1/2 of that, 1", is taking the load. If the there is 1000 lbs of tension on the forstay, that's 1000 lbs/inch. Now, make the pin too small, it's a point load of maybe 1/100". That means the load on that little point is 100,000 lbs/inch. That much pressure on any type of metal can cause problems. Most likely elogation of the hole or sawing into the pin, or both. Either way, a, $.89 bushing is worth the trouble.

BTW: A cute slim thing in high heels can generate 1000 PSI with each heel strike.