QCTP too tall

[WobblyHand]

Or you can use a left hand tool. I have two left hand threading tools, a Micro100 carbide one for small internal threading and a 3/4" Kennametal threading grooving bar. I thread away from the chuck with them. Single pointed a M8x1 internal thread with the Micro 100. No visibility into the hole. Just have to have confidence that if you do the right thing, in the right order, it will come out fine. Pays to practice first though!

The Micro 100 tools are awesome. But if you bump them or crash them, even an eensy bit, they snap. Otherwise they'll last a long time. I try to get them as surplus stock, because they are relatively expensive, especially if you snap one within 5 seconds of possession! That was a sad moment.

 

[chris.epp]

Stainless bearing steel is usually 440C, if it’s annealed, you might be able to turn it with your lathe, if hardened, not a chance. Take a file and see if it cuts it or skims across the surface. If it cuts it, then you might be able to turn it.

So.... I had tried just a bit on this stainless steel. It squeaked and felt sketchy so I stopped pretty quick. Then file tested it and can't get a file to bite at all... definitely hardened! Everything else so far seems so easy now though, and not terrifying. Hahaha

This shave was not easy going...

 

[chris.epp]

The problem with cutting metric threads on a lathe with an inch lead screw is that in order to resync the half nuts once opened is the lead screw has to travel some multiple of 127 turns. When cutting inch threads with an inch lead screw, you regain sync at least once an inch. Metric thread dials are a complex mechanism compare to the inch dials. This is because metric pitches are set up as mm/thread whereas inch threads are threads per inch.

It is possible to use the half nuts when cutting metric threads on an inch lathe.To do so, you make your first pass engaging the half nuts on a designated number on the thread dial. When you reach the left hand end of the thread, disengage the half nuts and shut the lathe motor down. Reverse the lathe and when you reach your designated number on the thread dial, reengage the half nuts and continue until you have passed the right hand end of your thread. Shut the lathe motor down and make your adjustments for the next pass and start the lathe in the forward direction. Repeat this process until you have completed your thread.

I think I need to work through your second paragraph on metric threads with indicator when I'm in front of the lathe. I was thinking if you disengage the feed then power off you were out of sync and can't really get it back for Metric. I'm probably not following right and have yet to use the threading dial at all yet so will revisit that when I'm there!