Alternate to a threading gauge . Line up to the straight edge of the tool shank.

I'm using a Iscar threading shank with a three sided cutter. And a threading gauge or two are available.

Consider a 1/2" bar with a square end. It's in a lathe collet. Line up the tool shank to be 90 degrees to the bar. No gauge used, just straight edges.
The contact area at the edge of the bar against the shank is long and easy to adjust on.

Is this a good practice - leaving the threading gauge in the tool box.

I hate trying to keep a gauge steady on cylindrical work while sighting down through a magnifying lens.
The contact edges are so short that the bit position looks correct in a small arc of adjustment.
For 32 tpi and above the level of error has to be low. So I ask because it bugs me.

rons said:

I'm using a Iscar threading shank with a three sided cutter. And a threading gauge or two are available.

Consider a 1/2" bar with a square end. It's in a lathe collet. Line up the tool shank to be 90 degrees to the bar. No gauge used, just straight edges.
The contact area at the edge of the bar against the shank is long and easy to adjust on.

Is this a good practice - leaving the threading gauge in the tool box.

I hate trying to keep a gauge steady on cylindrical work while sighting down through a magnifying lens.
The contact edges are so short that the bit position looks correct in a small arc of adjustment.
For 32 tpi and above the level of error has to be low. So I ask because it bugs me.

Click to expand...

Results are all that matters. What kind of threads are you getting? If your process gets you good threads, why question it?

Sent from my SAMSUNG-SM-G891A using Tapatalk

52 Ford said:

Results are all that matters. What kind of threads are you getting? If your process gets you good threads, why question it?

Sent from my SAMSUNG-SM-G891A using Tapatalk

Click to expand...

I don't know yet. The part came loose from the collet.

The process is a little different with brazed carbide bits. Have to use a gauge because the carbide is not aligned with the shank.
Unless the profile is re-ground into a straight position which I have done before.

With a insert tool it is easier and fast to setup with a straight edge. Yesterday I asked a question after a short length part released
from the collet and the thread was kaput. I already knew this might be considered a moot question. I was expecting to get something like:
"Everybody does it that way you forkhead".

what is a threading gage? a piece of metal with a 60° triangle in it? iv never used that in my life.

The threading gauge is going to be useful with a HSS tool that you grind yourself.
If it is shaped on a accurate machine then the shank would symmetric about the tip. And then you can trust what you made.

I have a box of brazed carbides that are all imported, just a few are U.S. made. I could dress all the threading bits to be
straight. Never thought about that till now. Or maybe migrate away from the Iscar. Got any ideas for threading insert holders,
store or homemade?

A catalog insert is likely dead true to center and both angles perfect off that point. Knowing your holder is holding that insert at a good right angle you can't do much better than going off the side.

But needing to grind your bit and then not knowing how to use a fish is like a teenager who has to call dad to change a flat.

I got this Iscar tool to get into tight places.

https://www.iscar.com/ecatalog/Ecat/datafile/PICTURE/677.gif

I ruined the second attempt to make the part by stopping the travel to the left too early. I think the head stock was in the way and it is much stronger
and bigger than my thready/teddy tool. A twitch like that and the bit runs down a good thread. The Hardinge two level operation has to be swift and at
the right time. I was too late on the retract lever. As long as the picture is here, any comments about Iscar made in Israel.

Depends on how critical it is to your finished product. What are the tolerances and class fit of the threads you are making? You can setup your tool post to be perpendicular to the workpiece and have the tool seat against the inside of the tool holder if repeatability is critical. If not, eyeballing it may be all you need to cut a functional thread. I have personally never used a gauge for checking this as those insert holders are designed to hold the insert at the proper angle, just get the shank of it perpendicular within a degree or two and off you go.

I could be wrong, but as I see it those fish tail, threading gauges are from the era of Armstrong tool holders and lantern tool posts. With those, the tool bit was often short (<1") and gripped by the Armstrong holder close to the tip so you were almost forced to use the fish tail gauge to ensure the tool bit was properly aligned to the work.

Fast-forward to the 1970s and the four way, indexing or quick change tool holders. The indexable tool holders and even the plain, HSS bits usually have one, STRAIGHT and somewhat longer side completely exposed so a simple square was all that was needed to align it. Indeed, with my own, shop made QC tool holder, I can align the tool post once with any tool and my threading tools will be aligned when I slap them on it.

The only real problems I see is if you are using a holder for inserts that does not have that built-in alignment feature or if, you grind a HSS tool that is not aligned to it's own shank.

I do have a couple of the fish tail threading gauges, but I mostly use them when I am grinding or touching up my HSS threading tools. My indexable tool holders do automatically align and I never have to worry about them. There are always some times where a special threading tool is really needed and I do know where my fish tail gauges are so I can break them out and use them on those occasions.

And as long as my threads will mate with the opposite part, I just don't spend even one second worrying about it. And if some old-fart machinist wants to tell me I am not doing it right, I will offer him a cup of coffee and simply ignore his advise.

QT: [And as long as my threads will mate with the opposite part, I just don't spend even one second worrying about it. And if some old-fart machinist wants to tell me I am not doing it right, I will offer him a cup of coffee and simply ignore his advise.]

I guess I am the old Fart you are talking about.
I would likely square to the part or up to a holder just like you advised if I knew that would give the correct angle with not using the fish..or use a fish if I was in doubt.
Better than scraping a part.

pretty sure that is wah I said.

Seem like to mention a fish is like telling somebody to eat asparagus, to somebody who hates asparagus.

Michiganbuck,

I guess I qualify for being an old fart too. Drop by some day and we will share some coffee and swap lies. Let me know ahead of time and I will pick up some donuts too.