PDA

View Full Version : Inserts for cutoff tools?



J Tiers
07-02-2015, 10:30 PM
I have some insert cutoff tools which I seldom use. But I wouldn't MIND using them (even though I tend to use plain ground HSS blanks), if I had more knowledge of the inserts.

The main reason I don't use them is that in 2 cases the inserts are missing or aren't in good shape, and I don't know much about the inserts or the method of inserting/changing them.

2 of the holders are from Newcomer, who apparently don't even make the holders anymore, or at least I didn't see them on the website. One of those is a nice thin one. The Newcomer holders do not have the hole for the lever to pop them in and out, so no clue there. The unreadable one is a NGTHR-19-4 instead of a 19-2

The other one is a Sandvik, R151.20-10-30. When I looked up the part number and wanted inserts, I got so many choices of insert that it was information overload. That one has no insert. It used to, and it's the one I used to use, but the insert popped out and got lost in the chip pan, so I don't even have its number (if it was still legible). I do not have the inserting tool, but I know what it is, and how it is used appears obvious.

The inserts look quite standard in shape, so even inserts for the Newcomer ones should be possible to locate among the available types.

Is there some sensible way to choose these things? Just the Sandvik site seemed to have dozens for that one holder alone.

Here they are
http://img.photobucket.com/albums/0803/jstanley/tooling/insert%20cutoff_zpsmwhr8ikg.jpg (http://smg.photobucket.com/user/jstanley/media/tooling/insert%20cutoff_zpsmwhr8ikg.jpg.html)

PixMan
07-02-2015, 10:52 PM
That top one takes Sandvik Coromant N151.2-300 inserts (3mm width), or N151.2-A125 (1/8" wide inserts), though Valenite VSG 3.0 N 30 inserts (3mm) or VSG 3.18 N 30 (1/8") also fit just fine.

If you find something and need to be sure it fits, just shoot me a PM. I have a huge library of catalogs, new and old, though that stuff I wrote is something I know off the top of me noggin.

I have the same tools in Valenite livery, and get inserts all day long off eBay for short money.

Here's a good one. LG is for "low feed rate", the 5735 grade is high cobalt binder content for toughness, won't chip.

http://www.ebay.com/itm/VALENITE-CARBIDE-INSERT-VSG-3-0-N-30-LG-5735-QTY-4-LOC1273D-/371237594599?pt=LH_DefaultDomain_0&hash=item566f7c25e7

Not such a great price, $10 each. Make an offer? They'll take it.

Toolguy
07-02-2015, 10:57 PM
The 2 bottom holders use an L shaped tool to cam the inserts out of the seat. The short part of the L is oval shaped so you insert the thin side then turn the lever to pry the insert out.

J Tiers
07-02-2015, 11:03 PM
The biggest issues were:

1) Knowing what the industry standard size was (assuming there is one) so I could weed down the sizes to what would at least FIT. A place with a cross-reference of size and manufacturer/holder would be just as good, and I'd assume that there would be one since inserts are somewhat aggressively sold and seem quite standardized.

2) A general purpose type of insert material and edge form. Just the Sandvik site had dozens of specific types/alloys/shapes or whatever, based on the exact material you'd be cutting, alloy-wise. And that was just for the holder I specified. Of course I don't KNOW the specific material, I might cut nearly anything (but no magnesium, no titanium, no uranium), and consequently these "specific manufacturing task related" cross references are not too useful to me, I want one that is decent for a wide range.

3) how the Newcomer parts were popped in and removed.

DR
07-02-2015, 11:19 PM
I always thought of the Newcomer as a less costly alternative to ISCAR. The style of inserts used were pretty much generic, lots of no-name verndors selling them.

The Sandvik's in my experience were unique to their own holders. And quite expensive at retail, maybe five times what the generic ISCAR style were available for. Sandvik's were definitely superior to ISCAR.

Considering that a popped out insert equaled a trashed holder with my machines running unattended I switched over to only top clamped inserts with a locking screw.

I still consider all of these insert type cutoff tools are poor choice for manual machines. Carbide works best at certain speed ranges, manual machines maintain the same rpm in parting. Relatively high surface speed at the outer diameter of the work piece approaching zero surface speed at the center of the work. A CNC varies the rpm increasing as the tool approaches center to maintain the ideal surface speed.

PixMan
07-03-2015, 12:36 AM
Cutoff tools are one area of turning tools where there are NO ANSI nor ISO standards. Period. The closest we ever got was the Iscar GTN/GTR/GTL type, which they have finally discontinued. Other companies like Newcomer will make them for years to come because the market is there with the "installed base." While popular, they are still not an ANSI nor ISO standard.

Therefore, proprietary inserts and mating holders in what you now find, and that Sandvik is also soon to be discontinued in favor of their newly introduced style.

DR, I'm so sorry for you that you feel that way about carbide insert tooling for manual machines. My manual machines run carbide insert tooling 95% of the time, and I know how to use it effectively. Education is the key. Try to run it like HSS and you will be sorely disappointed. The newer styles of insert cutoff tools would blow you away, and cost per amount of work they do is actually commensurate with HSS when used properly. I just recently changed the cutoff insert in the Valenite blade I have (takes the same inserts as the Coromant N151.2 system), and it had been in the machine for almost a year. I used it at least once a week, usually more.

Yes, a CNC lathe is capable of maintaining "constant surface speed", though cutting off to center they all max out and are ALWAYS cutting at "zero sfm" when you get to the center of a solid. That issue, the fact that its on a manual machine and sees a wide range of materials is why I recommended the 5735 grade I did, the grade can take serious abuse.

Oh yeah, JTiers, the way to get a GTN insert in is to use a piece of brass or other soft metal and tap it in. Place the soft metal below the cutting edge so you don't damage it, hit that with something heavier until it is seated.

J Tiers
07-03-2015, 12:58 AM
Thanks.

Maybe Newcomer makes them, but they don't seem to admit it. And they don't seem to make their own 19-2 style, or nobody I found had them. They did have the 19-4, which is quite wide (4mm?).

lakeside53
07-03-2015, 02:13 AM
you can get the 19-2 ...

http://www.use-enco.com/CGI/INSRIT?PARTPG=INLMKD&PMPXNO=949910&PMAKA=359-2192

I've been using 19-5 (0.120 insert width) for years on a 14 inch manual machine with no issues. I use an Iscar block to mount it in. You can still get the mount blocks and blades from Enco in the Hertel brand.

boslab
07-03-2015, 03:06 AM
I have a couple of similar holders, Sandvick TIZIT, or some such on the side, managed to bugger them both, need tips but importantly found out what was going wrong besides crosslide play, the tool seat of my 4 way toolpost was not flat, it was off by a few degrees, and curved, I knew it was curved but lived with that, looks like what I thought was wear was angle grinder surgery to allow the 4 clamp screws to level the tip hight without playing with packing, that worked to a fashion but it presented the tool to the work at an angle, hence parting tool failure, I must get a new toolpost but as an interim I (last night) milled one of the seats horizontal flat and square on my little Denbigh horizontal mill, boy was that lump of steel hard, it certainly took some cutting, I'm going to break out a new cutter for the other 3 tool positions.
Mark

J Tiers
07-03-2015, 10:40 AM
That insert LOOKS like the right one.... but so do a hundred or so others, without given dimensions...

How does one tell from the info given there that it actually will fit? That's the mystery to me....

DR
07-03-2015, 01:03 PM
That insert LOOKS like the right one.... but so do a hundred or so others, without given dimensions...

How does one tell from the info given there that it actually will fit? That's the mystery to me....

Yeah, no problem identifying the insert. For the Sandvik, call your local tooling, house tell them what holder you have and order a box of ten inserts for it, send a check for around $150 or more (I haven't bought for awhile). The insert identification will be right there on the box.

Okay, I'm not being serious, but that's about the way it goes. Then there's always the problem with used holders, there're as like as not to be sprung. As you said your Sandvik insert fell out.


Not too beat a dead horse too much, I don't consider these type self locking inserts good for manual machines, the light duty type most here have. Pixman has used the same insert for months, I bet his machine isn't a light duty import and for sure he has the experience to use insert tooling. Note also, most of the mainline insert outfits have dropped the spring locking insert designs in favor of the screw top clamp or other more secure locking.

J Tiers
07-03-2015, 01:38 PM
...
Okay, I'm not being serious, but that's about the way it goes. Then there's always the problem with used holders, there're as like as not to be sprung. As you said your Sandvik insert fell out.
...
.

It had help coming out....it did not "FALL" out. The part had shifted, and when I backed out the tool the insert was drawn out by the part. Not the holder's fault the insert came out, it was just as if I had actually levered it out.

Not an import anything involved.

I don't like the blade type holders, just look at the one bad review of the Enco linked to above... Yep, that's why, among other things.

PixMan
07-04-2015, 07:56 AM
J Tiers, I know for a fact that those inserts fit your holder. Valenite was/is part of the Sandvik Machining Solutions group of companies that includes Sandvik Coromant, Walter, Seco, Precision-Dormer, Safety (France, pronounced saf-UH-tee) and some smaller makers of PCD diamond tools. The "platform" for those tools was shared between Coromant, Safety and Valenite, though each made their own carbide for the toolholders. When Valenite was merged into Walter in 2010, the tools were discontinued by Walter in favor of their own system. In the past year, both Walter and Sandvik Coromant introduced new single-ended parting systems that are even more secure in the spring clamp design, and add coolant paths to the cutting zone.

I have the Valenite version of the toolholders and many inserts. Some of the inserts I've gotten are Sandvik Coromant and they fit into my Valenite VSG holders absolutely perfect.

The blade style that I have work exactly as well as the "monoblock" holder you have, trust me. You gain being able to go deeper when needed, you lose by having more bulk to the blade holder that moves the blade out away from the mass of the compound slide. That can be compensated by using the integral type 7-71 blade holder tool blocks and it's a wash. I'm not a fan of the GTx style insert because they don't have a positive stop and the center height changes as the insert gets pushed further into the holder as you cut. They are also far more prone to popping out. But those are extremely popular because they've been on the market first and longest.

bborr01
07-04-2015, 09:04 AM
I've got to agree with Pixman about using carbide on a manual lathe. I use the GTN type insert holder in a 18X40 lathe and I have been using the same insert for a few years and it does get used a fair amount. It just refuses to wear out. As Pixman pointed out, you need to run carbide fast. So the issue of too slow of sfm is not a bit deal.

A solid machine with the cutoff tool indicated perpindicular to the axis of the spindle and you can do some serious cutting.

Brian

PS. Pixman, it sure is nice of you to share your knowledge of inserts with us. Lots of that information is pretty hard to come by for older tooling.

Seastar
07-04-2015, 09:56 AM
Like (I suspect) many of us rank amateurs who lurk/post here, I know almost nothing about inserts.
I therefore never use them.
I wish the issue had some simple answers. Like buy this part for turning or this for cutoff.
Seems as though every post about inserts has strings of incomprehensible letters and numbers.
Isn't there some simple information available?
Bill

bborr01
07-04-2015, 10:00 AM
Yes there is a chart. I think mine is from carbide depot. I can't look it up right now because I am on my ipod. Google carbide insert chart and you will come up with one.

Brian

PS. I rarely use HSS anymore in my lathe.


Like (I suspect) many of us rank amateurs who lurk/post here, I know almost nothing about inserts.
I therefore never use them.
I wish the issue had some simple answers. Like buy this part for turning or this for cutoff.
Seems as though every post about inserts has strings of incomprehensible letters and numbers.
Isn't there some simple information available?
Bill

sawlog
07-04-2015, 10:55 AM
Like (I suspect) many of us rank amateurs who lurk/post here, I know almost nothing about inserts.
I therefore never use them.
I wish the issue had some simple answers. Like buy this part for turning or this for cutoff.
Seems as though every post about inserts has strings of incomprehensible letters and numbers.
Isn't there some simple information available?
Bill

Well it is confusing for all of us, I have been using inserts at the day job for years and there are so many different grades and chip breaker styles it can be over whelming.

My advice is to find a generic tool holder that takes commonly available insert that you can pick up at Enco, or E-bay and use a coated grade. That will cover most of the lathe work you are going to do at home.

Now on this topic I prefer to use the GTN 3 style blade inserts and for my smaller lathe I made a custom holder to use them, when I get the grizzly up and running I will use the same set up on it as well. You can adjust the blade to the diameter of the part unlike the others, plus the generic inserts are inexpensive, like it has been stated on this forum many times the best thing is to go slow on the spindle and carefully feed the cutoff tool.

Hope this helps

J Tiers
07-05-2015, 09:10 AM
......
Now on this topic I prefer to use the GTN 3 style blade inserts and for my smaller lathe I made a custom holder to use them, when I get the grizzly up and running I will use the same set up on it as well. You can adjust the blade to the diameter of the part unlike the others, plus the generic inserts are inexpensive, like it has been stated on this forum many times the best thing is to go slow on the spindle and carefully feed the cutoff tool.

Hope this helps

I like the type I have, because they are very stable, the blade cannot wander, it is supported by the rest of the structure.

The "insert blade type" look to me like a huge step backwards to the 1890s. Of all the types of cutoff tool I have used, the one I do NOT like at all is the old HSS blade type. I'd rather use one ground from a regular square blank.

PixMan
07-05-2015, 10:49 AM
J Tiers, you really have the wrong idea about blade type insert cutoff tools. Consider that you have the same insert in a blade style as you would the monoblock style you prefer. It's the insert doing the work, though it does depend upon the rigidity of the total setup to be successful. Each style works well, it all depends upon how you execute.

With the blade style you can move it in or out in the holder for reach or rigidity. Those also tend to give you far more steel under the insert for support. An important observation would be that for a given width of insert, both styles would have the exact same width of the steel, though the blade usually has more height. That height can be a disadvantage hanging out beyond the compound slide on some smaller machines. It still works.


https://youtu.be/Y52KJO9nX30

lakeside53
07-05-2015, 11:43 AM
I agree.... The "blade type" insert tooling works incredibly well. Zero issues and tough. I do use them in the dedicated holding block though.

J Tiers
07-05-2015, 09:27 PM
An important observation would be that for a given width of insert, both styles would have the exact same width of the steel, though the blade usually has more height.

The same thickness, yes, but NOT the same supporting material around it. Plus, I currently have no blade type holder, and I am quite uninterested in making one, and even more uninterested in buying one.

before you condemn me, recall please, that I am also perfectly happy using whatever suitable sized slotting cutter I happen to locate that was ground out of a regular tool blank. I "get it" about cutoff. I don't generally have any trouble using whatever i pick up. I just never liked the HSS blades, or their holders, and I don't see how the insert blades will be a lot different except for the insert itself and its geometry.

bborr01
07-05-2015, 11:05 PM
I'm probably wasting my time writing this because you seem to have your mind pretty well made up but one important difference in the insert cutoff tools is that the insert is wider than the holder, at least it is in the one that I use. When I ran lathes for 6 months in the late 70's we used HSS cutoff blades and carbide ones that were made the same as the HSS ones except that the carbide ones had an insert brazed in the top of it. If the cutoff tool gets out of perpendicularity to the piece being cut off it will bind on the blade back from where the cutting is supposed to take place. That is where some problems happen with cutoff operations. I can't even imagine trying to make cutoffs out of tool bits by grinding them down. Grooving tools maybe but not cutoffs.

Also, saying that you can't see the difference between the HSS blades and the insert blades except for the insert itself and its geometry is like saying that a cruise ship is the same as a canoe except that it has an engine.

I doubt that you would find many commercial job shops using much of anything but insert cutoff tools.

Brian


The same thickness, yes, but NOT the same supporting material around it. Plus, I currently have no blade type holder, and I am quite uninterested in making one, and even more uninterested in buying one.

before you condemn me, recall please, that I am also perfectly happy using whatever suitable sized slotting cutter I happen to locate that was ground out of a regular tool blank. I "get it" about cutoff. I don't generally have any trouble using whatever i pick up. I just never liked the HSS blades, or their holders, and I don't see how the insert blades will be a lot different except for the insert itself and its geometry.

J Tiers
07-05-2015, 11:45 PM
My mind is not made up, but my wallet is, for the moment, about the BLADE insert holders.

And don't forget, I HAVE USED insert cutoff tools. WITH THE SAME TYPE INSERTS. I am very well aware of the benefits.

Why else would I be looking for inserts for the insert holders I have?

I didn't have a toolpost slot to fit the two Newcomer tools, and the Sandvik insert got drawn out by the work and lost, or I might be still using it. (it did have a really wide kerf, and the one Newcomer is even WORSE).

Meanwhile, I used whatever, and made it work fine. In fact, I probably could use HSS blades and like them OK, now, I have lots of experience with worse tools.

The issue was how to know what insert fit the holder. That seems to be answered, but it is annoying that the previously standard holders are now obsolete and orphan. I don't much want to buy an insert BLADE type holder.

As for the insert blade vs HSS.... the insert holder is thinner and much more flexible than an HSS blade with the same kerf. The 2mm insert blade linked to above had one review, negative, due to that, for instance.

PixMan
07-06-2015, 06:53 AM
Just out of curiosity and not trying to sell you on anything, but what type of tool post do you have on your lathe? How do you hold onto a HSS blade if you use one?

J Tiers
07-06-2015, 09:01 AM
Just out of curiosity and not trying to sell you on anything, but what type of tool post do you have on your lathe? How do you hold onto a HSS blade if you use one?

I currently do NOT have an HSS blade holder, unless you count any old Armstrong type for a lantern post that might be in a box of junk somewhere. Got rid of the HSS blade holder, although some various sized blades did re-appear in toolboxes or assortments bought at tag sales.

I use a customized 4-way block most often as toolpost. I have another block type that I swap with it for large cutters over 1/2" square shank. Neither requires any wobbly stack of packing shims or other BS.