"Jeff Layman" wrote in message ...

About 20 years ago I bought a full-size stainless steel spade (made by
Griffin). It hasn't had a great amount of use.

Today I was trying to dig up an old variegated Euonymus. Its roots were
somewhat entangled with those of a 30-years old Chamaecyparis lawsoniana
'Ellwoodii' (which was cut down on Friday). I got half the Euonymus roots
cut through, then using one of the Ellwoodii roots as a lever point, pushed
down as hard as I could on the spade. There was a loud crack, and
something gave. I thought the plastic handle of the spade had broken, but
it was fine. The Euonymus was still in the ground. Pulling out the spade,
I was amazed to find that the blade had split horizontally about 3/4 of the
way across, an inch or two below where it became the shaft.

How could this happen? Stainless steel isn't brittle, and having split,
why didn't it split all the way across?

Probably due to metal fatigue. It's like breaking a piece of wire by bending
it back and forth several time until it breaks!
You have probably unknowingly bent it at that point many times before and it
bent back. This time it didn't:-)

Mike