Milk Bottle Locking Cap "Milkey"

Made this for a friend at work.. tried the 10mm version, but it was too large for a UK 2 pint milk. So made the 5 mm one instead. Fits like a Dream.

Used a screw, drilled the hole slightly bigger. The cut the screw to length. Super glued the screw in. Made sure it spins freely !!
Filed bottle top a bit as printer made it slightly too small. Glue gun used to stick top in.

On key, used an old small screwdriver (from a cracker). And cut the shaft to fit.
Glue gun this in the key.

Works a dream.. great design. :)
Fingers crossed my work colleagues don't just use a paper clip to open it !!.

Update..

Ive created a plasic key that can be printed and used to unlock the milk lid. Seems pretty sturdy and the plastic pins havnt snapped yet.
(Printing the key flat makes the pins stronger and less brittle).