First Try at Metric Threading

[Boswell]

Nice Nut !

 

[erikmannie]

This is 1” steel hex, 3/4” long. I made my best effort for surface finish on the facing. See also the 30° chamfer. The center drill is for an 11/16” tapered shank drill.

 

[erikmannie]

40° chamfer for the threading bar to head in:

 

[erikmannie]

So this time I was not at all aggressive with the DOC. The most I ever did was .005” radial, but I noticed that I was getting so many chips on the spring passes that I just start doing radial cuts of .002” max. You wouldn’t believe how many chips I was getting even on a third or fourth spring pass: it’s a mystery.

Surprisingly, I tested the nut after coming out only .04275”, and the nut could be hand tightened (with difficulty) all the way in.

I was very generous with the oil-based CF.

I’m going to go back to where I was and just do spring passes. I wonder if the insert will ever come out clean.

 

[erikmannie]

This is after 4 spring passes. A guy could overshoot it with spring passes.

 

[mikey]

Try a Micro 100 bar. They have the stiffness of carbide but cut like HSS.

 

[erikmannie]

This is what it looks like before I test fit the bolt:

 

[erikmannie]

While I had the chance, I did a concentric 40° chamfer and faced off .014” with HSS. 380 RPM, .009”/rev feed.

 

[Aukai]

Looks very nice.