PDA

View Full Version : Opinions on cutoff tools?



alanganes
11-27-2014, 07:49 AM
I've been slowly trying to upgrade my assorted tooling lately and have been toying with the idea of getting an insert parting tool. I seem to find myself doing these sort of cut-off operations fairly regularly and find the standard HSS or carbide tipped ones to be OK, but prone to chattering and the occasional "catastrophic failure" while in use.

I have used the blade type insert ones, like this:

http://www.use-enco.com/CGI/INSRIT?PMAKA=619-3837&PMPXNO=22919156&PARTPG=INLMK3

that I borrowed from the machinist at work a few times and found it to be miles ahead of the standard blade type. Looking around, there is also this style (which I have never tried):

http://latheinserts.com/1-2-INDEXABLE-PART-OFF-TOOL-404GTN20016.htm

Any opinions as to whether there is any clear advantage to one style over the other? Does one work better? I can see some theoretical increased rigidity to the second type, but that could be only theoretical, and there is the fact that the depth is a bit limited by the design. But again, that may be more of a theoretical rather than real limitation. Is there some other type I'm overlooking? Thoughts and opinions, please?

Discuss.

By the way of background, I just picked those two above somewhat at random as examples of what I was looking at. So I have no allegiance to either one. I'm looking to use this with either a 10x24 Jet lathe, or 10" Sheldon in AXA and BXA sized QC tool post.

Thanks, and for those observing in the US, have a great Thanksgiving!

PixMan
11-27-2014, 08:36 AM
Happy Thanksgiving to you too.

There's a couple of things to consider. With your AXA and BXA tool posts, you likely have the No.7 blade holders for HSS cutoff blades. These are useless for carbide insert tooling. My opinion is that when you get a tool that makes sense for your situation, you will never regret going with carbide insert cutoffs.

With using the blade style on a QCTP, you gain being able to use a variety of widths, from 1.5mm (.059") up to perhaps 5 or 6mm. The most popular is the 3mm (nominal) at .118", they often cut actual .122" wide. That does require buying additional blades for the different width inserts. The key to not blowing them up is to rationalize the insert width to how big a diameter you need to cutoff. Don't attempt to cutoff a 1/8" diameter workpiece with a 5mm (.197") wide insert any more than you'd cutoff a 3" diameter one with a 2mmm (.078") wide one.

Yes, the "monoblock" holders which can take the same inserts can be more rigid, but also more costly and limited. With a blade style, you could have the blade farther away from the block because of the holders. There are the No. 7-71 or No.71 style holders which are integral blade holders for direct to the toolpost, but I've not seen one in AXA yet. There are blade holder blacks that are clamped in a regular No.1 or No.2 holder, but those move the blade even further away from the support.

The blades tend to be about the same money as a monoblock holder, but blades usually give you two ends/pockets for the price, in case you have an accident.

In your case with two 10" machines you could use a 1/2" monoblock style in both, just be aware that the small monoblock tools are limited to cutting off perhaps 1" to 1-1/2" bars (or 1/2 that in wall thickness cutting to a bore.) With monoblock holders you can go to double-ended inserts for lower cost per edge. If interested, I may have a 5/8" holder for double-ended that I (or you) could machine an 1/8" off the bottom. Ping me via PM about it.

Toolguy
11-27-2014, 10:50 AM
I prefer the 2nd style. It is more beefy and you can clamp the inserts. You can do light turning with them as well. Both types work well. The main thing to remember is that parting tools can only go so deep before they will bind and break. If you need to go more than 1/2" deep you may want to seriously consider a bandsaw for that operation. Saw a little long and face to length.

outback
11-27-2014, 12:25 PM
Alan: Carbide is way better than straight high speed blades. The carbide inserts I have used cut a wide kerf so the blades have
clearance through the kerf.

The only thing, you are going to cry when you have a crash. I don't run very much production so I have a pretty conservative
tool budget.

I sure like the parting tool from Latheinserts.com. Looks like a nice tool for $35. I would like to order one.

The parting tool from ENCO appears expensive. Seems like I ordered one of those .093 wide for $80. That kind of parting tool
is probably the most robust and you get two insert holders per blade.
Jim

Glug
11-27-2014, 02:40 PM
There are a zillion options, all pretty confusing. I consider myself a novice at these, but here's how it went for me.

One way to go, and a great place to start, is to use one of the insert blades that are designed to be compatible with traditional old style HSS blade holders. You could get one of those and just stick it in your existing AXA cut-off tool holder. I lucked upon just such a holder for cheap from a local seller, an Iscar SGHS 4-17-3 with 18 inserts. It is a somewhat wimpy looking thing, but it works great. If you watch ebay you might do well on a used one, or one of the variations from the other manufacturers. The geometry varies depending on the holder you'll be using it in. The SGHS uses a common insert that could be used in other cut-off tooling.

In terms of the other solutions, I didn't like a lot of what I found - blocks, blades, blocks in holders, etc. But the Dorian 71C caught my eye as a great solution. I lucked out on ebay and found a couple at great prices (in CXA). But the SGHS has worked so well for me that I haven't gotten around to tooling up the 71C's. They apparently make an AXA version of the 71C, but it is a rare and very pricey thing. I think it would be a great DIY project.

I found the SGHS is best power cross fed at the proper rate. That is likely true of any insert based cut-off tool.

RussZHC
11-27-2014, 04:29 PM
Not that I will ever get to this project but I'm sort of partial to ones similar to the blade of your first example...IF you have the ability to machine your own tool holders that match the wedge tool post size you have, consider just making one up yourself (as opposed to the 71C) but I would make it for a size of blade that is more common and so have a bit more choice of insert (perhaps, maybe, at some point down the road). I'd go looking for one of the more common blades sizes and styles/makers hoping to lessen consumable costs and easy the finding of inserts going forward.

PStechPaul
11-27-2014, 06:52 PM
I found the following advice on the second type interesting:



[*=left]NOTE: MUST RUN .004-.005 ABOVE CENTERLINE TO PREVENT WORKPIECE FROM RIDING ON TOP OF INSERT AND BREAKING TOOL.


I had always heard that it must be dead on center, but in my experience and opinion it is better to run it a tad below center rather than above, as advised here. But this may depend on how the tool is sharpened, and positive rake (or chip-breaker notch) on the top edge may cause it to grab and dig in. Running above center will eventually have the tool face rubbing on the small diameter "nit" that remains, while below center will just cut at a sharper angle until it reaches 90 degrees and passes under the "nit" or "nub" or what ever you may call it.

bborr01
11-27-2014, 07:24 PM
Alan,

I have the Dorian version of the first one and love it. I regularly cut 2" steel with it and have never had a problem. The inserts seem to last forever. It came with the lathe when I bought it used about 5 years ago and I am still using the same insert that was in it when I bought it.

A few months ago I had a job where I turned a bunch of nylon up to 4" diameter and the parting tool was handy for the deep cuts that I needed to make. The one in the second link doesn't look like it would cut anything over maybe 2" in diameter.

I have priced out the inserts for the Dorian cutoff tool and they are fairly expensive buy like I said they last a long time so no worry there.

Back in the day I used a lot of HSS parting tools and they worked OK as long as you had a good solid lathe to use it in and sharpened it square.

Brian

oldtiffie
11-27-2014, 08:37 PM
I like both - the first is marginally better.

I prefer these - expensive - just sharpen on a standard pedestal grinder using the gauge provided - also see the 60 deg screw cutting tool:

http://i200.photobucket.com/albums/aa294/oldtiffie/Lathe_misc/I-Fanger3.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/Lathe_misc/I-Fanger2.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/Lathe_misc/Part_off4.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/Lathe_misc/Part_off1.jpg

oldtiffie
11-27-2014, 08:56 PM
I found the following advice on the second type interesting:



[*=left]NOTE: MUST RUN .004-.005 ABOVE CENTERLINE TO PREVENT WORKPIECE FROM RIDING ON TOP OF INSERT AND BREAKING TOOL.


I had always heard that it must be dead on center, but in my experience and opinion it is better to run it a tad below center rather than above, as advised here. But this may depend on how the tool is sharpened, and positive rake (or chip-breaker notch) on the top edge may cause it to grab and dig in. Running above center will eventually have the tool face rubbing on the small diameter "nit" that remains, while below center will just cut at a sharper angle until it reaches 90 degrees and passes under the "nit" or "nub" or what ever you may call it.

I always set my parting tool (sometimes the threading tools well) at least 0.005" above centre - 0.020" on bigger jobs is OK too.

A parting tool as well as a screwing/threading tool is a "form" tool after all.

These tools are inclined to "dive" down under load and setting the tool higher gets it back closer to being on centre under load.

A maths check will soon show that any change to the formed/turned part is minimal to the point of being inconsequential - same applies to tilting the screwing tool left (or right) to set the tool parallel to the thread helix (angle).

Tundra Twin Track
11-27-2014, 08:58 PM
I have the exact model in first pic,seems to work good a nice upgrade from HSS.I got a bunch of inserts for that model at auction 25 cents a piece so no brainer to go with it.Blade,holder and tool for install and removeal of inserts $250.00

alanganes
11-27-2014, 10:47 PM
Thanks for the replies, guys. Lots of good info here.

The flat blade type was the sort I had used, and it did seem a huge upgrade from the standard blade type. With the awareness that crashes are more costly, hopefully the increased cutting efficiency will make crashes pretty rare. I guess that is the general deal with insert tooling. I have a few rather nice insert turning holder that cut great but give me two edges for about 7 bucks. So bashing one is costly, but they work so well that I tend to avoid wrecking them. I still use plenty of HSS ground tools that I use for much of what I do.

Tiffie, those are different, I have not seen that style before. Interesting, thanks for the pics.

Sounds like the blade style may be the way to go. Nothing says I can't get both I suppose, but like a typical HSM type I prefer versatility and limiting cost somewhat is nice. Even if this only worked on the BXA post, that would be a good start. From the look of it, it would not be too difficult either make an AXA holder approximating the Droian 71C that Glug mentioned. I suppose it might not be too difficult to modify a cheap AXA holder of some other type to do the same thing.

PS - Pixman, will send you a PM on the double ended holder. Thanks!

metalmagpie
11-28-2014, 01:00 AM
When I owned a 9" South Bend, parting off was very frustrating for me. However, I found a good solution. I bought 2 kits from Metal Lathe Accessories (?), namely:
http://www.statecollegecentral.com/metallathe/S-4382.html
http://www.statecollegecentral.com/metallathe/MLA-6.html

The upside-down rear-mounted toolpost made all the difference for me. I suspect you will also experience rigidity problems with a 10" lathe. Maybe these kits would help for you. BTW, it is an option to pay MLA to have the parts machined for you.

metalmagpie

PixMan
11-28-2014, 08:15 AM
Setting a cutoff tool above or below center is just masking a bigger problem. If you're setting one .005" to .020" (0.13 to 0.5mm) above center because it'll push the tool down that much, you must have one very loose spindle or incredibly weak tool post. Fix that problem first.

The tools run just fine on center to no more than .002" or .003" above. Never really below because it could leave a bigger cutoff nib than necessary.

PStechPaul
11-28-2014, 06:24 PM
What is the best position when cutting off a hollow cylindrical piece? This may be tricky if the hole is rather large, like a piece of pipe, and especially if the bore is not quite concentric or has a weld line inside? I think it may be safer in such cases to run the tool below centerline so that it has essentially negative rake and the remaining piece will glance over the cutting edge or cause it to deflect down and away, rather than dig in and jam. But the safest way may be to use the parting tool to cut a groove almost to the inner surface, and finish cutting with a saw, followed by facing or otherwise cleaning up the edge.

Black Forest
11-29-2014, 07:09 AM
What is the best position when cutting off a hollow cylindrical piece? This may be tricky if the hole is rather large, like a piece of pipe, and especially if the bore is not quite concentric or has a weld line inside? I think it may be safer in such cases to run the tool below centerline so that it has essentially negative rake and the remaining piece will glance over the cutting edge or cause it to deflect down and away, rather than dig in and jam. But the safest way may be to use the parting tool to cut a groove almost to the inner surface, and finish cutting with a saw, followed by facing or otherwise cleaning up the edge.

I part off pipe all the time on my lathe. I have the cutting edge set as close to absolute center height as I can measure. So far never a problem using the Walter 3.1 wide inserts and holder.

alanganes
11-29-2014, 09:29 AM
OK so before I got too much further along into all of this one of our board members, Pixman, made me a pretty generous offer to help out. Not only did he make me a deal too good to pass up on a monoblock type insert tool (along with some inserts) he went a fair bit out of his way to stop by my place, deliver the tool, and spend some time in front of my lathe educating me on it's use.

All I can say is that this thing is awesome. Anyone considering getting a tool like this should just do it. I was used to what I was taught in a night shop class I took years ago, run slow, lots of oil, conservative feeds, etc. When Pixman was here and we put this in the lathe, I reflexively suggested that we had to get into a slower spindle speed, and he said "Why?" The part was a scrap of "some type of steel," 1" diameter, spindle was at 1050 rpm (as high as my lathe runs), power infeed at 0.004"/rev. I got a bit of moaning from it, so after experimenting feeding by hand a bit I upped the feed a bit to 0.006"/rev. Then it worked like this:

http://smg.photobucket.com/user/alanganes/media/HSM_Board/IMG_3919_zpsmpdyncd2.mp4.html

It was so effortless and fun that I made some washers, just 'cause I could:

http://img.photobucket.com/albums/v479/alanganes/HSM_Board/cutoffs_zpsc9f5b27b.jpg

I had to skim a bit off of the holder to make it fit the AXA toolpost on my Sheldon, so having done that, I gave it a try there. Being that deadly combination of excited at how well this worked and pretty stupid, I incorrectly set up my infeed. The Sheldon infeed sets up a bit differently from my Jet ( I know this but apparently forgot for a minute...), and was going almost double what I thought it was. Dumb move. So I managed to dig the tool in and damage an insert. :( My mistake. Consider it tuition, I guess.

The take away lesson is to pay real attention to your speeds and feeds and take the time to find what's appropriate for what you are doing and set up the machine to match. One I got it right, the results were the same on this lathe as well. Fast and easy.

I've never run a cutoff tool at speeds like this, so it was a bit unsettling at first. But the results were impressive. At least to me.

Thanks to Pixman for the offer to help out and for going considerably out of his way in doing so. Like wise to everyone else who has chimed in on this. Really nice people here and great food for thought, as always.

-Al

alanganes
11-29-2014, 09:38 AM
When I owned a 9" South Bend, parting off was very frustrating for me. However, I found a good solution. I bought 2 kits from Metal Lathe Accessories (?), namely:
http://www.statecollegecentral.com/metallathe/S-4382.html
http://www.statecollegecentral.com/metallathe/MLA-6.html

The upside-down rear-mounted toolpost made all the difference for me. I suspect you will also experience rigidity problems with a 10" lathe. Maybe these kits would help for you. BTW, it is an option to pay MLA to have the parts machined for you.
metalmagpie

I've seen these, though never in person nor ever used one. Those that do (like yourself) seem to really like them. I still can't quite get my head around why this is an improvement. Not saying it's not, just that I don't quite grasp the theory of why this works. What makes this work?

Glug
11-29-2014, 11:59 AM
I've never run a cutoff tool at speeds like this, so it was a bit unsettling at first. But the results were impressive. At least to me.


Definitely unsettling! The rate of infeed while parting with inserts seems pretty crazy. You set it up, and when you throw the lever stuff happens *fast*! None of that tentative and cautious hand-feeding approach, at least for me, that seemed to be the norm with HSS blades.

Being able to reliably part steel, time after time, without drama, is a game-changer.

lakeside53
11-29-2014, 12:08 PM
Setting a cutoff tool above or below center is just masking a bigger problem. If you're setting one .005" to .020" (0.13 to 0.5mm) above center because it'll push the tool down that much, you must have one very loose spindle or incredibly weak tool post. Fix that problem first.

The tools run just fine on center to no more than .002" or .003" above. Never really below because it could leave a bigger cutoff nib than necessary.


YES!

I set mine on center and never have the "diving" issue. 90% of the time I use my carbide cutoff tools, but I have a drawer full of quality HSS and the correct Dorian holder for it. HSS make it easy to adjust just a cut bias so it cleanly cuts off one face edge verse the other, and is usually for where "razor sharp" just works better - like with small parts that can't take the "blunt" carbide tool pressure.

I do have a very solid 14x40 with CXA. On my 10 inch EMCO, things weren't quite as simple, but removing the compound and replacing it with a solid steel block and the tool holder on top solved that. It's not like you need a compound for parting.

PixMan
11-29-2014, 01:08 PM
WOW!

You're a fast learner Alan! Great meeting you and I'll be back with a couple of inserts for you sometime next week.

I loved that video, because the chipform you got is EXACTLY what I was so anxious to show you but couldn't because the tool wouldn't quite come down to center. I'm so glad you got it all squared away and working so well.

PStechPaul
11-29-2014, 03:34 PM
Just a quick tip for Photobucket users - you can post the picture for display in the forum without actually going on Photobucket and having pop-up ads and such to annoy and distract. Get the URL of the image itself by right-clicking on it and selecting "copy image location", then paste it in the image tool for the forum. The actual URL of one of the images posted earlier is:

http://i200.photobucket.com/albums/aa294/oldtiffie/Lathe_misc/I-Fanger3.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/Lathe_misc/I-Fanger3.jpg

Abaker
11-30-2014, 03:24 PM
Thought I'd show the aftermath of mine and why I went out and got an insert parting blade. When I first got my big lathe I used what I had which was a way too small BXA tool post. I had to make a riser block in order for the tools to reach the center line. I had successfully cut off one part with a standard HSS blade and was working on the second when the compound kind of dipped and then jumped with a big Whump noise. Was much more exiting than it sounds. In hind sight I remember the sound of the cutter was different right before it caught. I think it was beginning to get dull and was requiring more and more pressure to cut. Finally must have flexed into the side of the grove.

It was a good lesson for me because I learned to be much more respectful of all that power. The spindle didn't miss a beat



Cutoff tool holder got yanked down pretty hard.

http://i1269.photobucket.com/albums/jj589/AndrewShawnBaker/CY16/Crash1_zps16e51701.jpg



http://i1269.photobucket.com/albums/jj589/AndrewShawnBaker/CY16/crash2_zps9413ad50.jpg




I cut the rest of the way with a hacksaw and you can see where the blade grabbed the side of the grove.

http://i1269.photobucket.com/albums/jj589/AndrewShawnBaker/CY16/crash3JPG_zps72ec0076.jpg

PStechPaul
11-30-2014, 06:42 PM
My gallery of failed cut-off (parting) tools:

This was a brazed carbide 5/16" toolbit in a set of five from Harbor Freight. I had just touched up the edges so that it had better clearance and a good cutting edge with a bit of rake on the top, and it was cutting pretty nicely until the shank just gave way. It looks like the carbide tip fractured and may have caused a bind, but the shank material was also probably cheap steel:

http://enginuitysystems.com/pix/tools/Parting_Tool_1144_800p.jpg

http://enginuitysystems.com/pix/tools/Parting_Tool_1145_800p.jpg

This one was a very small parting tool in a Harbor Freight assortment for a mini-lathe, and it was actually doing quite well, but I think the screw holding the blade had worked loose and instead of the blade cutting into the work, it was actually pushing back into the holder until it touched the work and snapped off where the threaded hole was the weakest point. Probably cheap steel as well. The blade was undamaged and seems to be good quality HSS.
http://enginuitysystems.com/pix/Parting_Tool_20140120_01_800p.jpg

http://enginuitysystems.com/pix/Parting_Tool_20140120_04_800p.jpg

PixMan
12-01-2014, 12:23 AM
Paul,

When it comes to tools (or pretty much ANYTHING), paying more for high quality only hurts once. Those dirt cheap Chinese tools are always attractive in price, but if you look around there's always a bargain to be found on the good stuff and you only have to pay for it ONCE.

madokie
12-05-2014, 01:04 AM
about 10 years ago when i worked in the machine shop of a plating buisness we had 2 lathes , and kept breaking the carbide cutoff inserts and thin insert holder, and this was on the newer tight big heavy Russian lathe.Boss told us to find a cheaper way since we weren't a production shop and could afford to be slower . we had a quick change tool holder for a different machine, we no longer had. we cut the dovetail so it would fit on the russian lathe tool holder and got a 1/4 or 5/16 thick cobalt cutoff blade.worked great, we didnt use fast feeds, fed it in by hand, and no more breakage.Happy boss ,Happy workers.thin blades dont need much side presure to break and getting a chip in between blade and part will do that instantly..some people with larger heavy lathes install cutoff blade upside down for that very reason so gravity will take chip away from work,along with coolant.small lathes risk breaking crossslide dovetails off casting running any tool upside down.Carbide is for hard metals and high speed production .Plenty of HSS machining was done prior to WW2.Just because someone sells a new fangled tool ,doesnt mean you need it..

PixMan
12-05-2014, 07:49 AM
....Carbide is for hard metals and high speed production .Plenty of HSS machining was done prior to WW2.Just because someone sells a new fangled tool ,doesnt mean you need it..

Carbide is NOT just for hard metals. No one is saying to buy carbide insert tooling because it's a "new fangled tool", this stuff has been out there for at least FORTY YEARS.

The most common mistake is to use a very thin cutoff for a large diameter work piece. The same goes for HSS and carbide insert tools; the larger the diameter the wider your tool should be. Did you notice how when you went to the wider cutoff it worked better?

When it comes to cutting tool the failures are more often a matter of misapplication of the tool rather than a poor quality tool.

alanganes
12-05-2014, 09:45 AM
I do agree that this type of tooling is not the only way to do this, but I paid less for this than what the last couple of HSS blades that I broke cost me. So it was sort of a no-brainer for me. I've done lots of parting with HSS tools, and while I have some nice insert carbide stuff, I do much of my machining with HSS anyhow because it does the job for me.

My only point here was that this particular tool seems to make this operation much more predictable for me. I think I would echo the earlier remark that paying the money for a quality tool only makes you cry once. After that, you have a silly grin every time you use it.


Edited to correct typo...

Black Forest
12-05-2014, 10:15 AM
"Carbide is for hard metals and high speed production "

I only use carbide tooling on my lathe and I don't do any high speed production in my shop. While I do do quite a bit of turning on hardened hydraulic cylinder rod I also do a lot of turning on just your normal old steel, C45 .

Madokie how wide was the insert parting blade and insert that you were using? Just think how happy the boss would have been if you used a wider insert and blade!

clive
12-06-2014, 10:18 AM
I have a small Chinese lathe and it is a shocker for breaking HSS parting blades, so I tried mounting it upside down and running in reverse. Works well and haven't broken a blade since I changed.

Rosco-P
12-06-2014, 11:19 AM
Carbide is NOT just for hard metals. No one is saying to buy carbide insert tooling because it's a "new fangled tool", this stuff has been out there for at least FORTY YEARS.


More than forty years.....snippet from the Carboloy website.

The innovative history of Carboloy dates back all the way to the 1920s, when a General Electric scientist started experimenting with tungsten carbide. In 1928 the Carboloy Department of General Electric was formed, making breakthrough advances in cemented carbide technology and their metalworking applications. In the following decades Carboloy's innovations.

alanganes
12-06-2014, 05:58 PM
I have a small Chinese lathe and it is a shocker for breaking HSS parting blades, so I tried mounting it upside down and running in reverse. Works well and haven't broken a blade since I changed.

Interesting. My lathe has a threaded spindle for the chuck mount, so running in reverse would not work so well. I'd need to do the rear-mounted toolpost trick, I think.

clive
12-06-2014, 07:20 PM
Interesting. My lathe has a threaded spindle for the chuck mount, so running in reverse would not work so well. I'd need to do the rear-mounted toolpost trick, I think.

Mine has a cam lock, the rear mounted tool post works well on some lathes. It was not really an option with my lathe.

steverice
10-25-2015, 12:05 PM
My gallery of failed cut-off (parting) tools:

This was a brazed carbide 5/16" toolbit in a set of five from Harbor Freight. I had just touched up the edges so that it had better clearance and a good cutting edge with a bit of rake on the top, and it was cutting pretty nicely until the shank just gave way. It looks like the carbide tip fractured and may have caused a bind, but the shank material was also probably cheap steel:

http://enginuitysystems.com/pix/tools/Parting_Tool_1144_800p.jpg

http://enginuitysystems.com/pix/tools/Parting_Tool_1145_800p.jpg

This one was a very small parting tool in a Harbor Freight assortment for a mini-lathe, and it was actually doing quite well, but I think the screw holding the blade had worked loose and instead of the blade cutting into the work, it was actually pushing back into the holder until it touched the work and snapped off where the threaded hole was the weakest point. Probably cheap steel as well. The blade was undamaged and seems to be good quality HSS.
http://enginuitysystems.com/pix/Parting_Tool_20140120_01_800p.jpg

http://enginuitysystems.com/pix/Parting_Tool_20140120_04_800p.jpg

I never would have guessed this kind of failure from a HF tool choice. Hmmmm.

old mart
10-25-2015, 06:24 PM
If you bother to research parting off with carbide insert tooling, the manufacturers always say set tool height about 0.004" high if parting solid. They should know better than anyone.

TN Pat
10-25-2015, 06:49 PM
When you can part 304 stainless, starting at 500 RPM at a 2" OD... at .006 IPR... it's pretty cool! An insert cutoff tool would be the first investment I make with a lathe of 10" swing or larger...

I regularly use a Hertel GS094-insert 3/32" cutoff tool where I work. Max cutoff of 1.5" OD, but it works well for that.

Ed ke6bnl
10-25-2015, 06:54 PM
I have been cutting up wood saw carbide blades and using the carbide tip in my parting tool holder but cutting out a .5 in section with the carbide tip attached on my 11 in. rockwell upside down and reverse with good results.

tlfamm
10-25-2015, 07:15 PM
I have been cutting up wood saw carbide blades and using the carbide tip in my parting tool holder but cutting out a .5 in section with the carbide tip attached on my 11 in. rockwell upside down and reverse with good results.

Couple of pix would be nice, Ed.

Mike Amick
10-25-2015, 11:44 PM
How do you cut the saw blade up. Novel/neat idea (to me) More info would be nice.

Richard P Wilson
10-26-2015, 04:00 AM
If you bother to research parting off with carbide insert tooling, the manufacturers always say set tool height about 0.004" high if parting solid. They should know better than anyone.
After many years with HSS parting tools, I'm a recent convert to insert parting tools, and think they are wonderful. What I have noticed is that if its set slightly low, so that the tool tip drags under the final 'pip', the edge chips off. Thats why I now set slightly (just a hair) high, don't know if its the same reason the manufacturers recommend a few thou high.
Being mean, and inserts being relatively expensive, I've discovered that when the edge chips off, I can touch up the edge on my green grit wheel. I can do this 2 or 3 times before a new tip is needed.

Ed ke6bnl
10-26-2015, 11:56 AM
How do you cut the saw blade up. Novel/neat idea (to me) More info would be nice.

I cut the pieces out with a cut off wheel in the 4.5in grinder with a thin disc. and a dremel works also, i did have troubles using them the normal way and went to using them upside down and lathe in reverse and cut some very hard spacers for a dune buggy rear spline shaft spacer, and like butter in aluminum.

http://i890.photobucket.com/albums/ac110/Edke6bnl/Tools/Rockwell%20Lathe/20151026_081552.jpg (http://s890.photobucket.com/user/Edke6bnl/media/Tools/Rockwell%20Lathe/20151026_081552.jpg.html)

http://i890.photobucket.com/albums/ac110/Edke6bnl/Tools/Rockwell%20Lathe/20151026_081542.jpg (http://s890.photobucket.com/user/Edke6bnl/media/Tools/Rockwell%20Lathe/20151026_081542.jpg.html)

Euph0ny
10-26-2015, 12:42 PM
I cut the pieces out with a cut off wheel in the 4.5in grinder with a thin disc. and a dremel works also...

Thanks! How do you hold those cut-out "parting tools" in the lathe/toolholder? Does it matter if your cuts from slicing up the saw blade are not perfectly straight and parallel?

old mart
10-26-2015, 12:42 PM
The sophisticated tip geometry gives the commercially produced tips a huge advantage, just imagine the R and D that goes into them. These tips are expected to perform in industrial applications. That said, Iv'e noticed on Ebay lately that there are now HSS blades with a bulbous top and a chipbraking groove in the top, an improvement on the simple tapered blade.

Ed ke6bnl
10-26-2015, 03:40 PM
Thanks! How do you hold those cut-out "parting tools" in the lathe/toolholder? Does it matter if your cuts from slicing up the saw blade are not perfectly straight and parallel?

I use the holder for parting blade holder of my aloris type tool post. and I do agree that a commercial one may work far better I have only used the Tee type HSS one with fair to poor results.

I also want to make it clear that I saw this done on another site and tried it, this one I did not come up with the idea. Wish I could find the person who wrote it up but I don't see it in my records.

ulav8r
10-26-2015, 11:01 PM
If I remember correctly, Sir John posted the sawblade trick years ago on this forum. He did not cut out strips though, he just removed one or two teeth to leave clearance above the tooth being used. A shop made holder clamped the blade and allowed rotating to the next tooth when one wore out.

Mike Amick
10-27-2015, 01:26 AM
If I remember correctly, Sir John posted the sawblade trick years ago on this forum.

Oh yea .. I remember ..

the stevo_tooth

Black Forest
10-27-2015, 05:41 AM
If I remember correctly, Sir John posted the sawblade trick years ago on this forum. He did not cut out strips though, he just removed one or two teeth to leave clearance above the tooth being used. A shop made holder clamped the blade and allowed rotating to the next tooth when one wore out.

What are you talking about? Don't you remember the Evanpart thread where Evan invented this? :cool:

Richard P Wilson
10-27-2015, 08:02 AM
What are you talking about? Don't you remember the Evanpart thread where Evan invented this? :cool:

No wonder he doesn't post on here any more.

RichR
10-27-2015, 10:29 AM
What are you talking about? Don't you remember the Evanpart thread where Evan invented this? :cool:

I'm sure that was intended as a joke, though I didn't find anything funny about it. Personally, I feel you owe Evan an apology.

Peter S
10-27-2015, 10:33 AM
This is an old thread, but in the first post, the OP's first link shows a Seco parting blade, the type I use. They are expensive because the whole blade is HSS, it takes carbide tips as per usual. However, if your tip fails during a parting operation, the blade is not damaged, being HSS it remains mint and waits for you to fit a new tip.

Great but expensive product.

Black Forest
10-27-2015, 10:58 AM
I'm sure that was intended as a joke, though I didn't find anything funny about it. Personally, I feel you owe Evan an apology.

I feel I don't! :cool:

RichR
10-27-2015, 11:16 AM
I feel I don't! :cool:

Yeah, no surprises there.

alanganes
10-27-2015, 07:07 PM
This is an old thread, but in the first post, the OP's first link shows a Seco parting blade, the type I use. They are expensive because the whole blade is HSS, it takes carbide tips as per usual. However, if your tip fails during a parting operation, the blade is not damaged, being HSS it remains mint and waits for you to fit a new tip.

Great but expensive product.

I imagine it is. As I mentioned way back in this thread, I came upon a too-good-to-pass-up deal on a monoblock type by Walter. I just used it a few days ago and still hold the same opinion I did at the time, which is pretty much: Wow! What a difference!

I still feel a bit surprised at how easy and predictable parting stuff of is with these tools. As another person commented, being able to do this operation without drama is something of a game changer.

I've no doubt that the Seco blade type is just as good. When you look at what a hassle exploding blades can be in broken tools, damaged work pieces and just aggravation, while expensive, the price is really not all that high. It's that "Buy good tools and you only cry once" thing.

The other thing I suspect is that actually paying attention to the appropriate speeds and feeds for the material, size of the part and the tool you are using will make a significant improvement in the outcome. Like a lot of us, I had a tendency to do that sort of seat of the pants style. Once I started paying attention (actually calculating SFM and looking up in-feed rates, etc) and got up the nerve to use the power feed, things got a lot less exciting. I'd expect that may be true even with the old style HSS tools.