Thread Cutting on the Lathe, Part One - Cutting Tool Geometry

[TomG]

I've been thinking about doing a series of videos on thread cutting for a while and this weekend to make it happen. This is the first episode and it covers cutting tool geometry of an external V thread and how it applies to the tool.

Tom

[Highpower]

Tom,

There are a couple of things you touched on in this video that I would like to see more videos on.

1) A demonstration of how you are able to grind the miniature internal threading/boring bar clearance and relief angles on those tools. It seems to me that you would need a razor sharp edge on a thin grinding wheel to cut the reliefs on those tools. Perhaps you could take the mystery out of that for me.

2) While I know it's not a common thread in most shops these days, I would also appreciate a video (or 2) on grinding and cutting with square thread tools.

And thank you for all your other videos that you have produced thus far.

[TomG]

Willie,

The smallest of those tools were probably ground on the wheel of a surface grinder, but only because it's easy to get a sharp corner on an aluminum oxide wheel and those were readily available on a surface grinder. I do have a 100 grit aluminum oxide wheel on my bench grinder and it would work equally well. The trick is to get a nice sharp corner, but the width doesn't really matter.

Square threads are on my "hit list", so you can expect to see a video on cutting them eventually.

Thanks for the appreciation.

Tom