Cracked Mast Step

[Bora]

The mast step on my 1991 Hunter 30T has cracked at all four corners, where the bolts attach. There is no cracking on the deck, the cabin top does not show signs of sagging, and there is no movement or "play" in the spar. A very reputable Seattle surveyor recently looked at it and was stumped. Any thoughts on what may have caused this?

 

[Saillife]

Just guessing here. Two things come to mind, over torqued bolts or maybe just a bad casting?

 

[Crazy Dave Condon]

Looking at the direction of the cracks from front going toward the rear would appear that either the mast is too tight on tuning to the rear or simply too much prebend beyoound what is called for.