On 02/11/2020 12:49, michael adams wrote:
"AJH" wrote in message ...
On 02/11/2020 01:01, michael adams wrote:
A shallow hole won't harm the tree in any way.

yes it will and a lot worse than using an aluminium nail, aluminium being for the
benefit of future sawyers, trees don't mind steel.

Aluminium nails are less harmful than lengths of wooden dowel, are they ?

Yes in that the penetration is immediatly sealed and very small compared
with removing a plug to a depth which likely compromises the tree's
ability to limit fungal action.