Is milling your own fixture plates worth it?

Just to verify, is this the threadmill you used?: #10 Solid Carbide Single Form Thread Mill 24-56 TPI x 1" Reach USA I20 — CarbideToolSource.com

I read on your post in What did you mill on your shapeoko today and there was a 1/4 threadmill linked

I just wanted to make sure I get the right tool before ordering