Lay down threading tool questions...

LVLAaron

LVLAaron

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Looking for a new high quality 16ER type laydown toolholder.

What role does the insert/bushing/shim play? (The part that would be under the insert) - They have 3 different pointy bits that all look a little different but I don't know why.

Also, what is the screw in the side of the holder, under the shim for?

Example:
 
I believe the shim is there in case of a crash. So you don't damage the tool holder. Just replace the shim. I once read somewhere or saw a video suggesting the taper of the shim on a threading tool is different depending on the diameter of the material.

I have no idea is any of this is true. But it's what I recall.
 
In some (the better) tooling the shim is used to adjust the slant of the insert to match the lead angle of the thread.
 
The shim provides support for the cutting edge of the insert and is replaceable in the event of damage.
Some tools have a screw on the side that clamps the shim, those shims have a notch where the screw clamps and are specifically right or left hand. (STM16R and STM16L) On others, the shim is simply retained by the same screw as the insert. Those shims lack the notch and are ambidextrous (STM16). https://www.aliexpress.com/item/2251832639946659.html

I've bought a dozen or more threading tools off Aliexpress recently, some are one type some the other, even in the same order.
Unless you are one of those people who brags about how much something cost, I would suggest you save yourself some serious cash and try those threading tools. They are well made tools with hardened shanks. Current delivery times to the west coast are 2-3 weeks.

www.aliexpress.com

8.31US $ 45% OFF|Ser1010h11 Ser1212h16/11 Ser1616h16/11 Ser2020k Ser2525m External Thread Turning Tool Ser Sel Lathe Cutter Bar Cnc Tool Holder - Turning Tool - AliExpress

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For laydown threading tools, the anvil is to accommodate thread helix angle. You can change the anvil for higher angle. Usually the anvil that comes with the tool covers most thread pitches. When you need to cut coarser threads (also depends on thread diameter) you'll need to change the anvil otherwise you'll get rubbing. The screw is to keep the anvil in place.

For turning tools, usually larger ones, the anvil is only to prevent wear of the tool, like from repeated heavy interrupted cuts.
 
See attached document which explains both the use of different anvils and also the differences between internal and external, right and left threading with laydown holders/inserts. Iscar, Carmex and Hertel (made in Israel) are the same holder, just the label is different. Hertel rebrands many other manufactures, but the pictures often do not match what you get. On a 1236-1340 I would go with a 5/8" holder, or a 3/4" which is what I use. I also recommend the Carmex threading inserts, I have found them to be very durable. I have been using the standard 16ERAG60BMA in all metals, but there are different types for specific materials and also full thread versions for a specific pitch. The side screw is probably to prevent the anvil from moving under pressure from cutting. I have not changed the anvil in mine, and I have cut from around 9 to 32 TPI, I also do a lot of metric thread cutting.

The downside of laydown inserts is mostly on internal threading of small diameters is limited by the holder/insert size, so a solid carbide thread cutter can be used for smaller diamters for short distances.

 

Attachments

  • Carmex Thread Turning Inserts Technical Section.pdf
    1.2 MB · Views: 13
mksj said:
On a 1236-1340 I would go with a 5/8" holder, or a 3/4" which is what I use.
Click to expand...
I have a 1/2" shank Carmex external that I used with my 8x14. I currently have a 12x36 & was going to "upgrade" to 5/8" like most of all my other tools until I saw the size in person. Even with a "CNC point" live center when single pointing small diameters clearance can be an issue. 1/2" to 5/8" isn't going to gain me any ridgity, no need to take heavy cuts while threading, & they both use the same size insert (16ER). I don't single point anything coarser than 16 tpi very much (I do have AG60 inserts too though) so I prefer the 1/2" tool size. Some people just grind a relief on the back side of the tool but I don't need to bother with all that sticking with what I already have.
20190731_200757.jpg

I also kept the Carmex internal bar from the mini lathe which can get me down to 1/2" internal thread but it can only use A60 11IR so it's limited to 16 TPI (AG60 11IR isn't available, too small). So I did get a bigger internal bar to use 16 IR inserts, also for larger diameter threads & to be able to use AG60 inserts when needed.
(Yes I do know they're mounted upside down, that's how I use internal threaders ;))
20210605_201723.jpg
 
mksj said:
See attached document which explains both the use of different anvils and also the differences between internal and external, right and left threading with laydown holders/inserts. Iscar, Carmex and Hertel (made in Israel) are the same holder, just the label is different. Hertel rebrands many other manufactures, but the pictures often do not match what you get. On a 1236-1340 I would go with a 5/8" holder, or a 3/4" which is what I use. I also recommend the Carmex threading inserts, I have found them to be very durable. I have been using the standard 16ERAG60BMA in all metals, but there are different types for specific materials and also full thread versions for a specific pitch. The side screw is probably to prevent the anvil from moving under pressure from cutting. I have not changed the anvil in mine, and I have cut from around 9 to 32 TPI, I also do a lot of metric thread cutting.

The downside of laydown inserts is mostly on internal threading of small diameters is limited by the holder/insert size, so a solid carbide thread cutter can be used for smaller diamters for short distances.

Click to expand...

Thanks. That's exactly what I was looking for.
If you haven't tried the UN inserts, give them a shot. I got 16/18/20 TPI inserts for barrel work. They provide a nicer end result.
 
One more question while we're all here:

Kennametal "LT 16ER Inserts" - Same thing as a regular 16ER? I understand LT stands for laydown threading, but wanted to make sure there's nothing proprietary about their system.
 
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