But he was asking for a tap and a die, so might of been scratch building a silencer setup. Jeez wish I never bloody bothered saying anything for amount of flak I've got trying to be helpful. If nobody gives you the info you want, take the valve out, get hold of a vernier caliper or micrometer and a good magnifier and work out the diameter of the thread and pitch. Then look up the figures in set of thread tables for what's closest. See if you can get a bolt or nut that size, to see if it's right before forking out about £30 or more on taps and dies.