Hmm 4mm x .7 is .1575 so .0025 clearance is good I'd think. The actual screws for holding inserts are more shaped like a bugle horn than counter sunk.
Inserts like the TNMG without countersinks...I'm thinking they usually have a post that acts as a cam to push the insert to the back and use a clamp to actually hold the insert. I could be wrong but that is why I went with TCMT for mine, well that and I have TCMT in hand also, then the relief built into the TCMT makes things handy for home made tooling.
Steve
Inserts like the TNMG without countersinks...I'm thinking they usually have a post that acts as a cam to push the insert to the back and use a clamp to actually hold the insert. I could be wrong but that is why I went with TCMT for mine, well that and I have TCMT in hand also, then the relief built into the TCMT makes things handy for home made tooling.
Steve