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914Wilhelm
09-23-2011, 10:37 PM
So, over the years I bought a fair amount of carbide tooling for lathe work. I've been overall satisfied I could remove metal fast but have been rarely satisfied with the finish. Recently I've been experimenting and impressed with HSS. My question is: Is there a source of HSS inserts that would work in my place of the carbide inserts in my holders? I ask because it's always a compromise between grinding my own and just buying something off the shelf. Right now time is a more valuable commodity than money. Thanks for ideas and resources.

gwilson
09-23-2011, 10:44 PM
There are HSS inserts available. I saw some in use some years at the Cabin Fever Expo in York,Pa.

I never use such,though. I just save the expense and grind my own tools. HSS will give a sharper edge than carbide(unless you have special equipment for grinding and lapping). Also it is much more shatter resistant for certain applications than carbide. For example,ever stop a carbide threading tool in the midst of a cut?

Scottike
09-23-2011, 10:52 PM
With the cost of HSS tooling stock, why would you bother? A 3 or 4 dollar piece of HSS can be regound/touuched up countless times before it's unuseable. Even with inserts, I touch off and re-calibrate, when I change inserts.

beanbag
09-23-2011, 10:53 PM
http://www.arwarnerco.com/

dp
09-23-2011, 11:02 PM
With the cost of HSS tooling stock, why would you bother? A 3 or 4 dollar piece of HSS can be regound/touuched up countless times before it's unuseable. Even with inserts, I touch off and re-calibrate, when I change inserts.


The value is split between the vendor and the machinist. How long does it take to grind an HSS tool vs dropping in a replaceable insert (not to mention repeatability and accuracy)? If you are a shop owner you can pay your help to build grinding jigs and stand over the grinder or pay the vendor to do that. The efficiencies of scale go to the vendor. HSS is not appropriate for everything and neither is carbide, so make wise choices and get the best of both *appropriate* worlds.

PixMan
09-23-2011, 11:12 PM
There are HSS inserts available. I saw some in use some years at the Cabin Fever Expo in York,Pa.

I never use such,though. I just save the expense and grind my own tools. HSS will give a sharper edge than carbide(unless you have special equipment for grinding and lapping). Also it is much more shatter resistant for certain applications than carbide. For example,ever stop a carbide threading tool in the midst of a cut?

Not in the long time, but then why on earth would I want to or have to do that? Today's carbide can take that if you got the right one, and it can be bought dead sharp (and hold that edge too.)

beanbag
09-23-2011, 11:17 PM
For example,ever stop a carbide threading tool in the midst of a cut?

Plenty of times with no problem. Maybe it's because I use a tough grade of carbide.

Scottike
09-23-2011, 11:45 PM
With HSS I can get Exactly shape I want or need, It would take a catalog of inserts to do the same thing.

firbikrhd1
09-23-2011, 11:52 PM
In my shop I use HSS bits ground to the shape I need exclusively. It's a hobby for me and time spent grinding my own bits is part of the "fun". Even so, I have considered the A R Warner tooling for internal and external threading, especially internal. Grinding tiny or short bits 1/4" or smaller to fit my boring bars is a pain and difficult to achieve accurately. Perhaps one day I'll pony up with the cash to go for the A R Warner tooling. For now it just doesn't seem cost effective.

dp
09-23-2011, 11:59 PM
With HSS I can get Exactly shape I want or need, It would take a catalog of inserts to do the same thing.

Never the less, you'll have to admit that carbide inserts are a pretty good industry to be in, so there must be a need for the pattern forms now available. Now suppose you have a shop with 10 machine operators and you need a tool of common form and which is widely available as a drop-in replacement. Carbide is not an option owing to material incompatibilities. Can you keep 10 machinists in cutters with repeatability and form accuracy all day long at a profit by grinding them? I think not, but there are some amazingly talented swarf makers on this forum.

In my own home shop I go to great lengths to avoid buying inserts of any kind, though. When Boeing Surplus went away I spent the last week there poking through the inserts bins buying everything I thought I might ever need from what was available. :)

Scottike
09-24-2011, 12:19 AM
I wish I could have been in the neighborhood when boeing surplus closed, I didn't find out until after the fact, One of my favorite places!
Carbide did indeed revolutionize the industry, for all the reasons you gave.
But there are still some things that HSS does better.
Each has their own place in the shop, and it doesn't have to be either/or.

Iraiam
09-24-2011, 12:48 AM
I have a few HSS inserts that I bought from little machine shop, they fit my insert tool holders that i also bought from them, real handy on the turret tool post if you want to switch between HSS and Carbide, as I do on many occasions. And then I use regular ground HSS in the quick change tool holders mostly.

Jaakko Fagerlund
09-24-2011, 01:01 AM
Yet again sounds like wrong kind of inserts/grade/chip-breaker/speed in what OP said. If one is going to use carbide inserts, it pays off to know how much surface speed and DOC and feed some insert needs at least so that it works as supposed to.

I pack two kind of inserts, one for general turning (tough grade) that is also suitable for finishing (R0.8 and R0.4 nose) and the other insert type that is suitable for turning aluminum (very sharp and lot of angle).

And if something needs to be done to higher precision than turning itself allows, then a grinder or emery paper needs to be pulled out as turned surface is too rough no matter what insert you use.

PixMan
09-24-2011, 08:20 AM
I also bought (and was given) a good many carbide inserts of varying shapes, sizes, manufacturers and grades in recent years. The only thing I've bought recently was the one Valenite parting blade and insert kit for $89.00, shipped. I'm done and don't see spending anymore for a time

It's often true that a HSS tool can give a better finish, but that's a function of tool geometry more than tool material today. Gone are the days of having only large corner-radius, heavily-honed, high-force inserts that demand big cuts, high feed, high speeds and abundant power. We now have some carbide inserts I have that truly mimic the very up-sharp angles of HSS bits, and they can run at 2x to 15x the speed of HSS. Or they can run happily at the same speed as HSS. I also have a good lot of HSS, and do use it now & then.

There's plenty of room for both. The biggest reason to avoid carbide is that of ignorance. With HSS tools if you run it too fast and burn it up or you're not getting desired chip control, it's two minutes later and you have a fresh edge and new geometry. With carbide, it's FAR MORE expensive and time consuming to find a more-appropriate grade/coating/chipbreaker. You might have something that works, probably not. Even I am ignorant of all the inserts available, though I do know more than many.

I'm just not understanding HSS inserts. The AR Warner stuff looks nice, but from what I can see, all flat-topped inserts offering little chip control. The inserts are generally about half the list price of current name-brand quality carbide, but I haven't paid list....ever. So they're about equal in price and I get long life and chip control.

gwilson
09-24-2011, 08:39 AM
I can't remember why right off,but for some reason,there have been a few times when something has gone wrong, or some other reason,and I've had to stop the lathe in a thread,popping off the carbide tip.

For turning stuff like ivory,I'd never use carbide. HSS cuts with a sharper edge and less force.

My machining most of the time is of an unusual nature,making parts for valuable mechanical antiques. I rely a lot on making special shapes with HSS lathe bits. Its just better for my class of work.

When doing something like facing off a large cast iron faceplate,cast iron just dulls HSS pretty quick,so I use carbide then,or when needed.

A needless expense,in my work,to buy HSS inserts.

rode2rouen
09-24-2011, 09:26 AM
My question is: Is there a source of HSS inserts that would work in my place of the carbide inserts in my holders?


My experience, which may differ from others, is this:

Warner HSS inserts don't work well in holders designed for carbide inserts, due, IMO, to the fact that most carbide inserts have the rake angle formed on the insert, while the pocket of the holder is parallel (0* rake) to the holder centerline.

The Warner holders I have are made with the rake (+7*, IIRC) machined into the pocket, and work well. HSS cuts well with positive rake, not so well with 0* rake.


Rex

Black_Moons
09-24-2011, 11:11 AM
Iv had a few cases where I *needed* 0 rake for HSS to cut properly. Mainly when doing plastics. Rake likes to dig in and rip the work outta the chuck -_-

Some of the exotic woods I have turned can dull super sharp HSS in a hurry. Not so sure carbide would last much longer (For the dollar...), as I hear these woods often contain silicon crystals.

Only takes a few licks with a lap to sharpen my super round nosed HSS tool, as long as I don't let it get too dull.

(Protip: The time between sharpening and the time spent sharpening is NOT linear. Time spend sharpening = Time between sharpening ^ 2
The duller it gets, the faster it dulls, And the exponetialy more material that must be removed

Jaakko Fagerlund
09-24-2011, 12:15 PM
Forgot to say that I have one or two "under plates" (don't know the Enghlish name for them) for the carbide insert holders that I have ground down from the business end. This is so that I can grind the carbide inserts to whatever geometry I need, mainly to have a sharp edge or no nose radius at all or a form tool, things like that. Sure I use HSS also, but in about 1 % of cases.

Boucher
09-24-2011, 01:11 PM
OP: So, over the years I bought a fair amount of carbide tooling for lathe work. I've been overall satisfied I could remove metal fast but have been rarely satisfied with the finish

Answer: You are not doing something right. You can get a good surface finish with carbide. It is easier with HSS but achievable with carbide. Most of the time it is about cutting speed, finish starts improving when the chips are coming off straw colored and gets better as they turn blue. There are carbide inserts that are specifically for finishing.

OP: Right now time is a more valuable commodity than money.

Sounds like it is time to stock up. I have been retired eight years and sometimes wish that I had bought more supplies back then.

I do like the A. R. Warner tools and inserts. I particularly like their vertical threading inserts in the positive 5° configuration.

I have a lot of quick change tool holders. The number loaded with inserts and HSS are probably about equal. The original grind on HSS takes me a while but I can touch one up faster than I can change an insert. I don’t take them out of the tool holder to do it. HSS inserts are ok but the old style tool blanks are the way to go for most situations. I was fortunate that I got a lot of old bits and ground tools with my lathe. These can sometimes be found at auctions. If you buy new (Asian) go for the better Cobalt grades.

The used tool box at an old machine shop can hold amazing examples of HSS grind configurations.

gwilson
09-24-2011, 01:20 PM
Black Moons: You are correct; some woods are pretty abrasive. Ebony is a wood that is hard on tools. Back in the 19th.C.,when those ornamental turning lathes,with their multitude of delicate,highly honed carbon steel cutting tools were used,African blackwood was preferred as it is much less abrasive. Their cutting tools' edges had to stay sharp all the way through complex spirals and other decorative cuts they made,so blackwood was used. It is a rosewood.

Arthur.Marks
09-24-2011, 02:42 PM
A few quick notes. I have used the AR Warner stuff.
*be SURE the toolholder fits the right insert, whether carbide or HSS.
*the HSS inserts with the flat top can be re-used a great many times if you want. You just flip them top-side down on a fine bench stone and hone the edge again. Same as re-sharpening the one you ground by hand, basically.
*the triangular inserts by AR Warner are a bit of an odd geometry, IMO, in comparison to most triangular carbides offered. The HSS uses 11° rake. The carbides I mostly run into are 7° rake. It makes a difference for which toolholders they each fit.
*following on the above, if I were to do it all over, the best of both worlds have to be the CCM_ toolholders and inserts. The CCMT toolholders which are now seemingly everywhere take the AR Warner CCMW HSS inserts interchangeably (pretty sure they need a different flathead screw, though).

beanbag
09-24-2011, 06:32 PM
umm, when you guys are talking about 7 degrees and 11 degrees, that is in reference to the RELIEF angle, not RAKE. The most common of the Warner inserts have 7 deg relief angle, since the second letter in their name is a C. There are some with 11 degree, with the letter P. I have never seen a toolholder with a pocket that tilts upwards, but I see how you could use that with an insert that has a 11 deg relief angle and no top rake, to turn it into something with top rake after all.

How well does HSS cut when there is no top rake? Also, what does the hole in the insert look like?

Arthur.Marks
09-24-2011, 09:32 PM
First, yes. Stupid mistake on my part. It is the relief angle---not rake. Next, according to the chart (http://www.arwarnerco.com/warner_products_inserts_chart.html), CCMT and CCMW should have the same ISO countersink angle. The only difference is that the former has a chipbreaker built into it. I swear, the plethora of insert terms, options, shapes, angles... is enough to make one crazy :eek: If I was running a shop for money, no doubt I would need a dedicated tooling salesman just to decipher everything. ISO vs. ANSI, toolholder vs. insert designators, all the designations which are interchangeable vs. those that aren't. It makes my head spin :(

Arthur.Marks
09-24-2011, 09:38 PM
Here is a good example of the finish, BTW:
http://watchmaking.weebly.com/tailstock-centers.html

rbertalotto
09-25-2011, 07:50 PM
In 30 years of being a Home Shop Machinist.......The single best turning tool I've found is the Diamond Tool Holder.

Until you use this bizarre device, you have no idea how amazing it is. Talk about easy to sharpen.....a monkey could do it. And on a home shop lathe the finish is fantastic in all materials.

http://www.bay-com.com/avactis-images/DTH10copy_2.jpg

http://www.bay-com.com/product-list.php?DIAMOND_TOOLHOLDER-pg1-cid35.html

firbikrhd1
09-25-2011, 10:27 PM
In 30 years of being a Home Shop Machinist.......The single best turning tool I've found is the Diamond Tool Holder.

Until you use this bizarre device, you have no idea how amazing it is. Talk about easy to sharpen.....a monkey could do it. And on a home shop lathe the finish is fantastic in all materials.

http://www.bay-com.com/avactis-images/DTH10copy_2.jpg

http://www.bay-com.com/product-list.php?DIAMOND_TOOLHOLDER-pg1-cid35.html

I couldn't agree more! It's a great too and I use mine 90% of the time. The remainder I use hand ground tools for special purposes.

rbertalotto
09-26-2011, 11:54 AM
It saddens me when I see home shop machinists struggling with all kinds of cutters and trying to learn bit grinding and sharpening when they simply don't do it enough to become proficient.

All they need is a Diamond Tool Holder and they will have surface finish they had no idea was possible on their smaller home type lathes.

Something about "you can lead a horse to water................."