What size T-fittings for MTI hose?

Hi, molding a vac port into a flange and would like to know the diameter of the hole I should create. Plan on using MTI hose, so I need to know the size T I should go with. 2 ends join the hose, 1 end exits through the flange where a vac line will plug in. The hole needs to accommodate the T and 2 wraps of tacky tape. Thanks.

Use a T with outer diameter between 8-10mm . That fits in the spiral inside the MTI hose.

Ive been using 1/4 nylon t fitting available at lowes.

This. They can be found much cheaper elsewhere, but in a pinch I grab them from Lowes as well.

How sensitive is the seal to od of the Tee? There’s a lot of difference between 8,10 mm and 1/4 inch.

Lol, tacky tape fits all the dimensions. Only concerned with that permanent hole dimension in my flange.