That is the range I was expecting. I am going to aim at 3,000 lb. with
a 4:1 safety factor. That will match the 7/16" Warpspeed halyard pretty
well.

The next question is what type of fitting should it be? I am thinking
either to mill a piece of 1/2" x 2" 316 and drilling for a 1/2" pin for
a shackle or bending up a ring out of 1/2" rod.

Stephen Baker wrote:

Glenn,
I once asked Shore Sails in RI that question, and was told that they didn't
really know..... In the end I calculated what load the tack ring could take,
and used that plus 50% as a basis. Size the tack line to be the first thing to
give, for a little extra piece of mind.
As a guide, I have used 2500lbs on a 40-footer, and 5000 lbs on an Open 60.
Tack fittings still in place. ;-)

Steve

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com