30 seconds of Google and I found this
Banned in the UK
flick knives (also called 'switchblades' or
'automatic knives') - where the blade is hidden inside the handle and shoots out when a button is pressed
butterfly knives - where the blade is hidden inside a handle that splits in two around it, like wings; the handles swing around the blade to open or close it
disguised knives, eg where the blade is hidden inside a belt buckle or fake mobile phone
gravity knives
sword-sticks
samurai swords (with some exceptions, including antiques and swords made to traditional methods before 1954)
hand or foot-claws
push daggers
hollow kubotan (cylinder-shaped keychain) holding spikes
shuriken (also known as 'death stars' or 'throwing stars')
kusari-gama (sickle attached to a rope, cord or wire)
kyoketsu-shoge (hook-knife attached to a rope, cord or wire)
kusari (weight attached to a rope, cord or wire)
This is not a complete list of banned knives. Contact your local police to check if a knife is illegal.
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