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(03-31-2012, 10:47 AM)PixMan Wrote: Apart from the pitch-specific full-form (a.k.a. "cresting") inserts, there are A60/AG60/G60 "partial profile" inserts that are capable of making threads of a wide range of pitch, though the sacrifice is that they have a .002" (A60 & AG60) or .007" (G60) tip radius and they don't create the thread height themselves as the full-form ones do. The A60 or AG60 are the ones to have no matter what, so you're not stuck not being able to make a thread if you don't have the perfect cresting insert on hand.
That should be enough to generate questions!
Ken
Ken,
Can the same tool hold both types of inserts, both cresting and partial? I have a Kennametal threading tool and some of the partial profile inserts and was wondering if I can use the cresting inserts with that tool.
Thanks,
Ed
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03-31-2012, 03:11 PM
(This post was last modified: 03-31-2012, 03:23 PM by PixMan.)
(03-31-2012, 12:58 PM)EdAK Wrote: Ken,
Can the same tool hold both types of inserts, both cresting and partial? I have a Kennametal threading tool and some of the partial profile inserts and was wondering if I can use the cresting inserts with that tool.
Thanks,
Ed
Ed - Most certainly, YES. My advice with this is to first buy the partial profile, then next get the specific pitch or pitches that you use most often.
Also download the Vardex "TTGen" software from the Vardex threading tool website. The anvils under the threading insert may need to be changed to match the lead angle of the threads you wish to make. The coarser the thread and smaller the diameter of it, the more likely you are going to need to change the anvil underneath the insert, as this is the part of the tool that matches lead angle.
Note: Vardex uses a different set of numbers than the rest of the laydown threading world, as does Sandvik Coromant. However, unlike Sandvik Coromant, the Vardex and others are completely interchangeable.
A Vardex "3ER" is everyone else's 16ER. Likewise a Vardex 2ER is 11ER in other lines, and a 4ER Vardex is a 22ER to everyone else. The Coromant are a different thickness to others.
http://www.vargus.com/vardex/template/de...&pageId=74
Your LSASR 103 holder takes any 16ER / 3ER inserts.
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Ken,
Thanks for the info. I bought just partial profile inserts so that's all I have for it. Now at least I know it can use the cresting type if I need them in the future.
Ed
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Rarely in a home shop is it a matter of "need" cresting type inserts, rather it's a "want". Once you've used them, there's often no going back!
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(03-31-2012, 03:25 PM)PixMan Wrote: Rarely in a home shop is it a matter of "need" cresting type inserts, rather it's a "want". Once you've used them, there's often no going back!
OK, so I best not get any then.
Ed
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The problem with the cresting inserts Ed, is that they make this too easy.
Let's say you were making a 1/2-13 UNC thread. Now normally you would turn the diameter to something less than .500, so perhaps .496/.494 as that's the recommended diameter. With the cresting inserts you would leave the pre-threaded diameter at .500, and let the insert bring the O.D. down to finished sized. When you reach it, the pitch diameter is done too. Works every time.
You'd learn to love the beautiful, burr-free smooth threads such as you see here in the 316 stainless steel motorcycle axle I made for a friend:
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Ken,
You shouldn't have shown me that picture. Those are some nice threads and in SS none the less.
I may have to get one of the cresting inserts just to try them out. I know, probably not a good idea.
Ed
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Ohh, it's such a slippery slope this technology thing,
in the old days we used to believe there was no point in carbide threading tools except on automatics as the speed of manual threading was rarely high enough to use the benefits of carbide, but then the full form inserts came out and made it viable, but where do you stop? as threading with a full form carbide tip can be done at near to normal turning speeds so the next step is auto stopping the threading process or do you just go straight to CNC?
For hobby purposes I set the limit at HSS threading, to keep the costs down, if I need speed then it's no longer a hobby is it?
Having said that My aim is still CNC at which point I will re-assess my stand on carbide threading as at that point partial form carbide threading tools will be the minimum standard of tooling able to cope with the speed available.
Rick
Whatever it is, do it today, Tomorrow may not be an option and regret outlasts fatigue.
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Hi
Lads
I have been having problems with a 8 tpi lead screw for my mill
Yesterday a friend gave me a 8 tpi "form tool" tip
This fitted my screwcutting tool holder
The pictures show the results on a bit of 3/4 stainless
The tool was wound square in to the work (not at 14 deg)
Now all i need is a bit 1 inch diamiter 24 inches long threading
John
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