On Thu, 22 Nov 2018 16:09:53 +0000, Brian Gaff wrote:

Even I have heard of this. They normally put it down to stresses in the
fixing or the assembly of the unit. You then only need a tiny flaw and
stress and temperature tend to make it fail.

She's replying to a 2014 post Brian - situation normal for H.O.H.

--
TOJ.