Piston V.S. Wedge AXA QCTPs Question..

[PeterT]

Thread directions with pictures

Please school me on internal threading, tool holders, inserts, HSS etc.

I'm looking for someone to educate me on the finer points of internal threading. As a baseline, I've never internally thread anything. I recently ordered some tool holders/carbide-inserts from Aliexpress, and the learning curve on the insert/holder naming conventions was pretty steep. When I...

canadianhobbymetalworkers.com

Just a caveat if you have screw on chuck, reverse spindle direction will act in a loosening direction (providing load is high enough).

 

[Susquatch]

Hope I've clarified things a little.

I understand and use all those techniques@Dabbler. I find them especially useful when inside threading a blind hole.

I was just wondering what @Tom O was asking. His question wasn't clear to me. I'm thinking your answer probably addressed his question though because you basically covered all the bases - except maybe the relief angles issue which he also asked about.

 

[DPittman]

Rats..... requires running the lathe in reverse.

Well you can thread from the other side without running the spindle in reverse as long as you have the option of a reverse tumbler on your carriage feed.

 

[YYCHM]

Well you can thread from the other side without running the spindle in reverse as long as you have the option of a reverse tumbler on your carriage feed.

And get a RH thread? I don't think so....

 

[Susquatch]

And get a HR thread? I don't think so....

What is an HR thread? Or did you mean LH thread.

I think I need a vaca. I can't seem to understand much of anything that people are saying....... And no, I have not been drinking......

 

[YYCHM]

What is an HR thread? Or did you mean LH thread.

I think I need a vaca. I can't seem to understand much of anything that people are saying....... And no, I have not been drinking......

Me bad, RH thread. Sorry

 

[Susquatch]

Well you can thread from the other side without running the spindle in reverse as long as you have the option of a reverse tumbler on your carriage feed.

At the risk of one more dumb question. What is a reverse tumbler?

 

[Susquatch]

Me bad, RH thread. Sorry

So, did you do a double bad and mean LH?

 

[YYCHM]

So, did you do a double bad and mean LH?

No, I meant RH. Seems you can't turn a RH thread traversing away from the head stock without running the spindle in reverse no matter how you look at it. I have a threaded spindle, so running in reverse is a problem for me.

By reverse tumbler, I think he means the ability to reverse the lead screw independently from the spindle.

 

[DPittman]

And get a RH thread? I don't think so....

Sorry I misspoke, you are correct. That always gets me confused, I have to turn my hands in the direction of the spindle and leadscrew for it to make sense! Leadscrew and spindle going in same direction then rh threads...

 

[DPittman]

"By reverse tumbler, I think he means the ability to reverse the lead screw independently from the spindle."

Yes that is exactly what the term means.

 

[Susquatch]

My lathe has a Lever on the Headstock that reverses the leadscrew direction.

I've never heard it called a reverse tumbler.

I wonder where the name comes from. Sounds like it might be an interesting story!

 

[DPittman]

My lathe has a Lever on the Headstock that reverses the leadscrew direction.

I've never heard it called a reverse tumbler.

I wonder where the name comes from. Sounds like it might be an interesting story!

Here is a picture of my reverse tumbler. It simply reverses the direction that the gears that operate the lead screw.

 

[PeterT]

I think its a thing!

 

[Susquatch]

I think its a thing!

Yup, I guess it really is a thing!

Here is a nice photo that I think explains why it's called a tumbler gear. The two gears appear to "tumble" one way or the other. This one also changes ratio, but it is a great visual.

I learned something cool!

Thank you everyone!

 

[Tom O]

What I was trying to refer to was the threading insert it has a positive rake and if you rotate it 180* the cutter isn’t made to be flipped like that so do they make a insert (l/r) or holder to accomplish this? I’m going to have to watch Joe‘s video again lol.

 

[Susquatch]

What I was trying to refer to was the threading insert it has a positive rake and if you rotate it 180* the cutter isn’t made to be flipped like that so do they make a insert (l/r) or holder to accomplish this?

Within limits, thread pitch and size affect the clearance requirements of the thread cutting tool bit both in terms of the tip shape (which affects the cut quality and the root shape of each thread) and the angle of the edge trailing away from the tip (you called it rake - but I prefer my own terminology) which is mostly determined by the thread diameter and the thread pitch.

The same tool geometry will cut both outside threads (front forward and rear reverse), and the opposite trailing edge (your rake) angle tool (LH tool) will cut both inside threads (front inside in forward and rear inside in reverse).

Left hand threads are the opposite. Outside RH tool tips cut inside LH threads, and Outside LH Tool tips cuts inside RH threads.

If you buy preground hss or carbide inserts, you will find that they generally only sell RH and LH tips. But RH outside = LH inside, and LH outside = RH inside.

Does that help?

 

[Susquatch]

do they make a insert (l/r) or holder to accomplish this?

A few more thoughts.

Yes, they make holders that will take indexable carbide or indexable HSS tool bits that make threading internally and on the backside in reverse a bit easier. They look a bit like a lathe boring bar. This makes it easier to get at the backside on lathes without a really long Cross-Slide.

I like hss over carbide. My bars and bits are made by a company called Mesa tools. When I got the link for you, I noticed that they don't make hss inserts anymore.......

5/8" Dia. Thread & Grooving Tool ID/OD GT | mesatool

5/8″ Threading Tool....... (One tool only...More than one shown)Thread ID/OD forwards, backwards, upside down.Cutting edge of insert is on centerline!Actual size: .624 dia X 4.5″ long, flats on 4 sides.Min bore is .710.Heat treated tool steel with black oxide coating.Threading inserts are .093...

www.mesatool.com

My tools are 5/8. They make other sizes. I'm sure there are other companies that make similar tools and perhaps take more popular standard inserts.

 

[Susquatch]

A few more thoughts.

Yes, they make holders that will take indexable carbide or indexable HSS tool bits that make threading internally and on the backside in reverse a bit easier. They look a bit like a lathe boring bar. This makes it easier to get at the backside on lathes without a really long Cross-Slide.

I like hss over carbide. My bars and bits are made by a company called Mesa tools. When I got the link for you, I noticed that they don't make hss inserts anymore.......

5/8" Dia. Thread & Grooving Tool ID/OD GT | mesatool

5/8″ Threading Tool....... (One tool only...More than one shown)Thread ID/OD forwards, backwards, upside down.Cutting edge of insert is on centerline!Actual size: .624 dia X 4.5″ long, flats on 4 sides.Min bore is .710.Heat treated tool steel with black oxide coating.Threading inserts are .093...

www.mesatool.com

My tools are 5/8. They make other sizes. I'm sure there are other companies that make similar tools and perhaps take more popular standard inserts.

I looked at my threading tooling just now and I painfully discovered that I lied to you @Tom O .....

Apparently it wasn't Mesa Tool who sold the HSS Threading Inserts. So I can't be pissed at them.

It was actually Arthur R Warner Company (ARWarnerCo.com). They made (and still do make) a variety of HSS Inserts and HSS insert holders. I do love them.

I also note that their inserts are neutral - they do not have a LH / RH rake (trailing edge). The Insert holder below comes with two inserts, each with 3 points that can be rotated as they wear out. One is for steel, and the other is for non-ferrous metals. They can be purchased separately.

The tool holder below is also double ended. One end can be conveniently used like a boring bar to cut inside or backside threads, and the other end can be used for regular front side, outside, and both left & right hand threading.

Kit #18 1/2 inch Threader NV

www.arwarnerco.com

As mentioned, they also sell other indexable tooling.

In this case, I do endorse their products and have had great success with them!

I only wish my memory was better.

 

[DPittman]

I looked at my threading tooling just now and I painfully discovered that I lied to you @Tom O .....

Apparently it wasn't Mesa Tool who sold the HSS Threading Inserts. So I can't be pissed at them.

It was actually Arthur R Warner Company (ARWarnerCo.com). They made (and still do make) a variety of HSS Inserts and HSS insert holders. I do love them.

I also note that their inserts are neutral - they do not have a LH / RH rake (trailing edge). The Insert holder below comes with two inserts, each with 3 points that can be rotated as they wear out. One is for steel, and the other is for non-ferrous metals. They can be purchased separately.

The tool holder below is also double ended. One end can be conveniently used like a boring bar to cut inside or backside threads, and the other end can be used for regular front side, outside, and both left & right hand threading.

View attachment 18013

Kit #18 1/2 inch Threader NV

www.arwarnerco.com

As mentioned, they also sell other indexable tooling.

In this case, I do endorse their products and have had great success with them!

I only wish my memory was better.

Ha ha that's kinda funny because I have a Mesa threading/grooving tool and have hss insert from AR Warner for other tool holders but thought to myself "I didn't think hss inserts were an option for that Mesa tool but I must be mistaken again" so I didn't question your statement. The only time I seem to speak up is when I am wrong.