I think it’s. 1/4 x 20.
Well, I have been hanging my RIB
, usually with a 20 HP outboard
, and 750 W of Solar
on then for I guess three yrs now and they have been fine.
I did have an incident with a lock when the lock cleat broke and the bow of the boat
came around, shoving the Davits
into the wall of the lock. The H brace that holds the panels
and separates the Davits bent, the Davits swung around with no damage. I bent the H brace back straight and all is well with the Davits.
I still have to replace the Radar
pole though, it creased and is not repairable, however it’s bracing also bent and was easily bent perfectly straight again, straight enough that you can roll them on a flat surface and detect no wobble.
Most of Kato’s “stuff” is highly polished 304, yet remains relatively rust free.
You will almost certainly need the flat bars to reinforce your railing if you mount the Davits, and if your at all concerned about hanging excessive weight on them, go with dual flat bars on each side. The Davits seem to be stronger than what they are attached to in most cases.
Call them, they are easy to work
with, and you can order any individual part at any time you need it in case you have to. They are a custom shop, not a large manufacturing facility.
The bottom of the Davits mount is a ball and socket joint, this allows angles that are not 90 degrees from the Davit to the hull
. The bolt that fits into the ball joint is not removable.