On 10/05/2021 19:16, alan_m wrote:
On 10/05/2021 18:30, RJH wrote:


There really isn't enough to grip with mole grips etc.; penetrating
oil - good
plan (although the ones that did come out were more stiff than tight);

Irish screwdriver?Â* Try inserting the hex bit and tapping with a hammer
which may shock any tight bond loose before attempting to undo.

Amn impact driver may also work - it hammers the bit in at the same time
as turning.


Remarkably effective technique, but 4mm is a bit small IMHO.