John Cuthell said:...But, is it that much of a problem to put tools in the hold of an aircraft?...
Im guessing youre right, John. So long as the bladed items are in the luggage that goes in the aircraft hold.
A while ago, I made up a first aid kit for a friend who was making a trip to India and Bangladesh. The kit contained items like disposable scalpels and a variety of syringes with needles, and bandage scissors etc, and these items didnt cause any kind of problems at all (It went in their luggage that was destined for the aircraft luggage hold). My guess would be that the same is true of larger blades, as your recent experience seems to bear out.
Something that might be useful when travelling with normally un-lockable luggage such as rucksacks etc, would be to put them in a thin, pack transportation bag that can be zipped and the zips locked with one of the Customs approved locks (these can be opened with a key that is issued to Customs so that they dont have to break the locks open on luggage should they want to inspect the contents).
The rucksack transportation bag also helps to avoid the straps on the sack from getting caught up in luggage conveyor machinery too, not to mention providing a minimum of protection against unwanted access to an otherwise unsecured sack during transit.
This is the type of sack cover Im speaking of (scroll down to Lockable Rucksack Bag):
http://www.safariquip.co.uk/acatalog/Rucksacks.html
Customs approved luggage locks (handy for securing Ortlieb type dry bags with D rings, also):
http://www.tsa.gov/travelers/airtravel/assistant/locks.shtm
Best regards,
Paul.