Carbide on a SB9"

QuickChange · Jan 24, 2018

Does it make any sense to use carbide (insert type) turning tools, for general machining on the smaller lathes like the SB9"? Currently, I use "insert type" Arthur Warner HSS tooling in my AXA toolpost for general machining. These have been working out very well, and I like them mainly for the easily replaceable cutting edges (3/per insert), and they are very easy to sharpen when needed. However, I have been eyeing the carbide tooling from latheinserts.com marketed toward hobby lathes, specifically the 3/8" or 1/2" kits. The geometry of these carbide inserts is supposed to be tailored to the lighter cuts usually taken on the smaller machines. The kits include 6 inserts. Four are PVD coated for steel/stainless steel, and two are polished inserts for aluminum. If you can believe the pic shown on their website the finish produced on the aluminum workpiece looks VERY good indeed. Does anyone have any experience with these kits? Recommendations good or bad for using carbide on the smaller machines?

iwananew10K · Jan 24, 2018

Yes, they work wonderfully.

It gets very expensive though.

balibalistic · Jan 24, 2018

Man I'm never happy with carbide on my sb9. I find a good sharp hss tool works great. I have a large heavy lathe and I love using carbide on it. Carbide loves high speed and big cuts. The little sb9 lathes just don't have the speed and rigidity imo.

Now are you saying that you are able to find inserts that are hss and not carbide?

QuickChange · Jan 24, 2018

balibalistic said:
Man I'm never happy with carbide on my sb9. I find a good sharp hss tool works great. I have a large heavy lathe and I love using carbide on it. Carbide loves high speed and big cuts. The little sb9 lathes just don't have the speed and rigidity imo.

Now are you saying that you are able to find inserts that are hss and not carbide?

balibalistic: I think the difference on the insert tooling from latheinserts.com is in the geometry/finish of the carbide. This supposedly allows a decent finish even when used at the shallower depth of cut, and slower FPM speeds used on the smaller (they refer to them as "hobby")lathes. And yes, HSS "insert type" toolholders are available from the Arthur Warner Company. They work very well, but the initial pricing is higher than just plain old HSS "blanks" (grind your own). You pay a premium for the convenience of easily replaced HSS inserts, but then, it's pretty hard to wear the inserts out. You see, the inserts can be sharpened MANY times very quickly and easily using some type of surface plate (glass, granite, flat steel, whatever) and a piece of 400 or 600 grit wet/dry sandpaper. Only the TOP of the HSS insert needs to be honed and you have three new cutting edges per insert. I do like them.

for iwananew10K: Thanks for your carbide comment as well. I take it then, that you are very happy with the finishes produced. For use on AXA sized toolpost/holders, would you prefer the 3/8" or the 1/2" size from latheinserts.com? Any advantages one way or the other? The only thing I can think of is perhaps the 1/2" size might be more rigid? But considering I would be using it on the AXA size post, would it really matter...

balibalistic · Jan 24, 2018

Neat! Can someone post a link or send me a link to these hss SVD carbide inserts?

I generally make my own tools for three fun of it.. But I'm sure not everyone has a row of industrial belt grinders like me. So it may be time consuming on an old stone wheel. I'd sure be happy to get a couple packs of hss inserts to fit my carbide tools. Would be wonderful for some operations

iwananew10K · Jan 24, 2018

Arthur Warner Co. | Specialists in High Speed Steel

As for the latheinserts.com kits as Curtis proved those out on a 7" mini lathe you really can't go wrong.

tobnpr · Jan 24, 2018

I use the Warner threading inserts as well. But... I broke down and ordered (being delivered tomorrow) a few hundred bucks worth of inserts and tool holders after speaking with the rep. Yes, advances have made certain carbide grades that don't need to be pushed as fast nor to the same heavy DOC. He also mentioned that many try a few speeds/feeds and just give up saying "can't run carbide on a manual machine" before putting in the time to experiment to find what works

Me, I'm mainly interested in laydown full-profile inserts, as I do a lot of Class 3 threads and they'll cut absolutely perfect thread pitches. I'll let you know how they work out. Also ordered some carbide TNMC for the Warner holder for pitches that I don't have the FP insert. Also, DCMT for tight turning to a shoulder,and WNMG for "all around". Just installed the new 1hp inverter motor and VFD- so I'll see what the old girl can handle before the V-belt slips

Cole2534 · Jan 24, 2018

QuickChange said:
balibalistic: I think the difference on the insert tooling from latheinserts.com is in the geometry/finish of the carbide. This supposedly allows a decent finish even when used at the shallower depth of cut, and slower FPM speeds used on the smaller (they refer to them as "hobby")lathes. And yes, HSS "insert type" toolholders are available from the Arthur Warner Company. They work very well, but the initial pricing is higher than just plain old HSS "blanks" (grind your own). You pay a premium for the convenience of easily replaced HSS inserts, but then, it's pretty hard to wear the inserts out. You see, the inserts can be sharpened MANY times very quickly and easily using some type of surface plate (glass, granite, flat steel, whatever) and a piece of 400 or 600 grit wet/dry sandpaper. Only the TOP of the HSS insert needs to be honed and you have three new cutting edges per insert. I do like them.

for iwananew10K: Thanks for your carbide comment as well. I take it then, that you are very happy with the finishes produced. For use on AXA sized toolpost/holders, would you prefer the 3/8" or the 1/2" size from latheinserts.com? Any advantages one way or the other? The only thing I can think of is perhaps the 1/2" size might be more rigid? But considering I would be using it on the AXA size post, would it really matter...

1/2" tools from latheinserts.com in an AXA post is a great way to run a 9, IMO.

As far as not getting a great finish, I call BS. No, you won't be creating a mirror but the parts will be very nicely finished and you can tickle off a .00025"doc if you want to. Granted that was on a 6061 piece and I had great SFM, your actual results may differ.

iwananew10K · Jan 25, 2018

I went for the 3/8", not that it's any better but because I had this set of boring bars and it let me use just one size insert for everything, and the smaller size insert let me get closer to the tailstock center...I had 3 primary turning tools- 3/8 RH CCxx,LH CCxx, and a RH DCMT(profiling), between those,the boring bars,and a good selection of HSS bits I didn't want for anything else.

These are nice little bars, Seco coolant thru, and a very good deal.

JTS Machinery & Supply Co.

steve-l · Jan 25, 2018

This subject has been hashed over on this forum many, many times. Please search the archives for an in depth review of this subject. However, one thing that has not been mentioned is that not only does the small hobby lathes not like carbide tooling, carbide tooling does not like small lathes either. You will find that insert life will be drastically reduced over the use time of the same insert on a stouter lathe, thus amplifying the large cost differential between carbide and HSS.

Further, inevitably inexperienced users want to reinvent the wheel and insist on the use of carbide on these old , small, plain bearing spindle machines. So be it. These machines were designed for HSS not carbide. It is far better to acquire a proper tool grinder with tilting table and protractor like a quality Baldor equipped with aluminum oxide wheels and learn how to sharpen HSS correctly. Under no circumstance can HSS tools be correctly sharpened with sand paper. Even the use of a common bench grinder is difficult and at times frustrating to get the tool correct.

iwananew10K · Jan 25, 2018

the old arguments against carbide simply do not hold true anymore. Edge geometries and insert composition has come a LONG way.
there is merit in learning with HSS...lots of lessons there.

as Cole notes the tools we are talking about can take incredibly light cuts at low speeds and leave a fantastic finish.

It's a new world now, and it can even make good sense to rough with HSS and finish with carbides...for some guys it makes sense to go carbide completely and reserve HSS for form tools.

There is no grinding and ensuing mess, and doesn't typically require cutting fluids, unless cooling is the goal...that right there can be a huge plus for some.

Let your wallet,goals and circumstances dictate what you choose.

steve-l · Jan 25, 2018

iwananew10K said:
the old arguments against carbide simply do not hold true anymore. Edge geometries and insert composition has come a LONG way.
there is merit in learning with HSS...lots of lessons there.

as Cole notes the tools we are talking about can take incredibly light cuts at low speeds and leave a fantastic finish.

It's a new world now, and it can even make good sense to rough with HSS and finish with carbides...for some guys it makes sense to go carbide completely and reserve HSS for form tools.

There is no grinding and ensuing mess, and doesn't typically require cutting fluids, unless cooling is the goal...that right there can be a huge plus for some.

Let your wallet,goals and circumstances dictate what you choose.

I cannot disagree with your comment, but it isn't inclusive and therefore a bit biased. Yes, many improvements have been made with carbide tooling, but there has also been just as much, if not more improvements with HSS alloys, manufacturing processes and quality. However, the use of carbide require tool forms that use less relief angles and blunter nose shape in order to prevent chipping and edge failure. The required carbide tool forms induce greater tool loads, which the machine must support and there is the rub. The lighter machine cannot support these tool loads without some sort of machine deflection and perhaps vibration. So, can these carbide tools be used on light machines with light cuts? Sure, but why? Where's the added value over HSS? It sure as hell isn't economy.

tobnpr · Jan 25, 2018

Agreed it certainly isn't economy. But time is money, and there's always going to be inconsistencies in hand ground tooling esp as relates to nose radius- at least when I'm doing the grinding/stoning.

No time wasted at the grinder, and once the optimal feeds/speeds are determined it's dial and make chips. As I said, I'm mostly interested in full profile threading. I never thought it would be compatible, but I've communicated with a couple of individuals using it successfully on a small manual machine.

mmarquette · Jan 25, 2018

[

Now are you saying that you are able to find inserts that are hss and not carbide?[/QUOTE]

Thumbing through the Travers tool catalog I saw inserts that are Hss. Don't reacall the sizes or the shapes but they are there. Not a huge selection but does open up other options

QuickChange · Jan 25, 2018

mmarquette said:
[

Now are you saying that you are able to find inserts that are hss and not carbide?

Guys---I'm sorry my original post created some HSS/carbide controversy, it was NOT my intention. for MM: The Arthur Warner company is THE go-to for HSS insert tooling. Iwananew10K posted the link to their site, check out their stuff. For "steve-l"--- says you cannot properly sharpen these HSS inserts using sandpaper, but I have done it many times and they cut just like new. Works for me.... Bear in mind I'm talking about inserts that are NOT severely worn and about using silicon-carbide "wet/dry" sandpaper placed on a flat surface like a surface plate or similar. The insert is sharpened by removing it from the toolholder and inverting it (this to work the TOP surface only, NOT the sides). Using a bit of honing oil, apply finger pressure to the insert and work the top side only of the insert in a circular pattern until satisfied with the appearance of the cutting edge. All I'm talking about is "freshening" the cutting edge. It's only necessary to remove (at most) a couple thou or so. Obviously, a surface grinder would be the better way to go if you had one

Now that I guess I have stirred things up a bit, just for sh-ts and giggles I'm going to purchase the 3/8" carbide kit from latheinserts.com. I will report back (assuming there is any interest?)after I have had an opportunity to use the kit.

iwananew10K · Jan 25, 2018

Don't worry, that pot is perpetually stirring.

You will love your new tool...Curtis know his stuff.

michiganbuck · Jan 25, 2018

Think everybody should be comfortable with both carbide and HSS. You can’t beat just flipping an insert and for hard work with inserts and you cant beat having a quick made special with HSS. For some the cost savings is important for HSS users..The one or the other only is jot very smart.

Derek Smalls · Jan 26, 2018

I agree with michiganbuck completely. Also, I think what most of you are overlooking is that the tool material, while important in many aspects, is really secondary in this discussion. The machine has no idea what the tool material is, nor does it care, what's important in this discussion is cutting edge characteristics.
Carbide inserts have not traditionally, and MOST still do not, have a very keen cutting edge. This has to do with the way they are made and also to help the edge hold up longer. If viewed under magnification, the edge looks slightly rolled over compared to a nicely traditionally ground HSS tool. Carbide inserts usually do not have as positive a rake angle as most ground HSS tools as well. This causes them to not cut as cleanly and produces higher cutting pressures, which certainly does not work well on small, less rigid machines.
BUT, what happens when a carbide tool IS ground to a keen edge? Doesn't it perform the same way as a tool made of any other material would with the same geometery? Only difference is it will last longer if run at the same speed!

Piglet · Feb 10, 2018

Good info here guys thanks

jim rozen · Feb 10, 2018

No! Never use carbide tooling in a small lathe like that, it will exploded on contact! Worse your lathe hates carbide and
will provide unfavorable yelp reviews for you as a machinist. Your work will be ruined and your machine will be permanently
harmed.

Right - seriously.

Use proper inserts, with positive rake. Avoid carbide for interrupted cuts. If you are using brazed tools, get a small diamond
wheel to keep them sharp. Otherwise, have fun!

Carbide on a SB9"

Aluminum

Diamond

Aluminum

Aluminum

Aluminum

Diamond

Hot Rolled

Diamond

Diamond

Titanium

Diamond

Titanium

Hot Rolled

Cast Iron

Aluminum

Diamond

Diamond

Stainless

Plastic

Diamond

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