Cutting depth on a standard acme thread 3/8's 10

That's your basic thread depth to start with. BUT, you have to add .010" to the resultant for the correct depth, to get the proper clearance in the thread. The exception to this is if your cutting a Centralizing thread like a 3C fit.

Ken
I have no idea what you are on about, please explain.
 
OK so I made a plug gauge to get some practice. Certainly worked out better than the first test on some garbage stock I had. Before you begin to get on me for the knurling I know it's a fail. I lost track of where I was and it's what it is. I did 3 wire measuring(size .0550 for 3/8's 10 tpi) at .401 Should have been about .406. I will probably make another one closer. It's 1.5" of thread the relief cut at the beginning was cut in .070 (.140) deep. I did run into trouble and broke the first one as I was not supporting the end with a center. I knew better as the overhang was too far. It did flex on me quite a bit. So I did a lot of spring cuts after each pass. I was cutting .005 per pass after the first pass at .010...at the end it was .003 cuts. Lots and Lots of cutting fluid to keep things smooth. After all was done I did knock down the burs with a file lightly while turning on the lathe. This is a right hand thread. I need a left and will also make that next. After which I'll make a set for 7/16's 10's right after I finish the next one.

Then new screw for both the cross feed and compound feed.


Paul
 
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