Weapon, Tool or Tent Peg ?

[Robert]

Picked this up recently and really have no idea of what it is. Looks like it could be a dagger, a spear tip or some kind of tool. Possibly a reworked bayonet / trench art? It has the #906 stamped into the round portion of the blade and a heavy hollow copper grip or ferrel. Any and all help in identifying what it is and where it might be from will be greatly appreciated. Thank you. Robert

Total length 13-1/2"
Blade length including round section 9-5/8"
Blade at widest 13/16"
Blade at thickest 1/4"
Grip Length 3-7/8"