What do I need to do this?

[Annette Elmore]

Hi all.

I'm an aeromodeller and have a small lathe.

I've made some venturis like the one in the photo.

The hole on the side of the venturi is threaded 4mm fine pitch.

What I need is a bit that will create a round flat recess around the 4mm hole so that the needle valve assembly will seat properly and create a good seal.

I ordered a flat 8mm mill bit but it was not what was needed.

Sorry to be a bit wordy but I didnt know another way of describing what I'm after.

Annette

 

[Phil Pascoe]

You've posted in Hand Tools - hopefully a mod. will shift your post to Metalworking - you've a better chance of getting an answer there than from all us wood butchers.

 

[Annette Elmore]

Thanks

 

[Annette Elmore]

I have added it in the right place can I delete this one or a mod do it for me!