I want to remove a bolt which takes a 4mm hex alan key - well it's not
quite that simple. The hex hole has a central pin which prevents the
insertion of a standard alan key. It may be a useful security feature but
nobody knows the wherabouts of a suitable key so it's a problem.

Ayone know if suitable alan keys can be obtained anywhere? I can't find
such things via screwfix.


It is almost certainly another kind of anti tamper key rather than the
classic hexagonal Allen key type. Any decent hardware shop should have a
suitable bit to fit.

Peter Crosland