I am having trouble finding a bit i need for a job , i need to cut some internal threads so i am after basically a v grooving bit but with the cutting edge facing outwards.

this is similar to what i am after

V Groove Bit

I have found a 1/2 " shank bit on ebay but was after something a bit smaller, i am not looking to spend a lot as its only a one off job

Anyone ever purchased a a bit like this before or know where to get one?

regards
Adam