If you have a recent boat with a Selden mast pay attention:
Selden had made a recall on the forestay fittings of some of their masts (2004-2008). The piece has the reference - 517-914. Here is the piece photo and all information:
Seldén Mast AB
The failures can happen on long distance cruising using only the genoa and Cracks are along the weld on the underside part of the fitting and will not be visible.
Many boats affected, between them: Arcona 460, Bavaria 46, Dehler 47, Elan Impression, Finngulf 44, Hallberg Rassy 40, Maxi 1300, Najad 460, 400,405,440, Omega 46, Salona 45, Sweden Yachts 42 and 45, Southerly 42, Van de Stadt 44, and Etap 46.