Another insert thread

[Downunder Bob]

If you are really not keen on grinding HSS tool bits get yourself a Tangential tool holde4r from Eccentric Engineering, only one facet to grind and angle is not that important, you can also get a sharpening guide with the tool holder.

Just look up "The Diamond tool holder from Eccentric Engineering"

 

[Ianagos]

Personally I think the hss over carbide is much over preached there are very few times when hss is better than carbide.

Look at YouTube of a guy name Stefan Gotteswinter he has small lathe and uses carbide insert getting very good finishes.

You can take small cuts with carbide insert but you have to get the right stuff. Don’t get an insert made for a rough turning when you only have 1/2hp.

I think many have had a bad experience with carbide due to the very cheap and extremely plentiful triangular cabide inserts and holders that are well absolutely terrible. There are not any machines that can make those useful.


Also I heard some people say absolutely stay away from Chinese and if you have the money you could do that and you will actually probably be a little better off but you’ll spend 10x as much money as the Chinese inserts.

I run large cnc machines and I buy expensive inserts at times but I’ve in some cases had better luck with a Chinese made insert then a very expensive name brand one. Both were material specific insert with the same coating and geometry but the Chinese carbide lasted much much longer and could be run way harder.

 

[Jim F]

If you are really not keen on grinding HSS tool bits get yourself a Tangential tool holde4r from Eccentric Engineering, only one facet to grind and angle is not that important, you can also get a sharpening guide with the tool holder.

Just look up "The Diamond tool holder from Eccentric Engineering"

That is an interesting design.

 

[DavidR8]

Personally I think the hss over carbide is much over preached there are very few times when hss is better than carbide.

Look at YouTube of a guy name Stefan Gotteswinter he has small lathe and uses carbide insert getting very good finishes.

You can take small cuts with carbide insert but you have to get the right stuff. Don’t get an insert made for a rough turning when you only have 1/2hp.

I think many have had a bad experience with carbide due to the very cheap and extremely plentiful triangular cabide inserts and holders that are well absolutely terrible. There are not any machines that can make those useful.


Also I heard some people say absolutely stay away from Chinese and if you have the money you could do that and you will actually probably be a little better off but you’ll spend 10x as much money as the Chinese inserts.

I run large cnc machines and I buy expensive inserts at times but I’ve in some cases had better luck with a Chinese made insert then a very expensive name brand one. Both were material specific insert with the same coating and geometry but the Chinese carbide lasted much much longer and could be run way harder.

If I recall correctly Stefan also grinds/hones his inserts on a CBN wheel.
I use CCMT inserts and HSS on my SB 10K. For peeling off lots of metal either work well.
My recent experience has taught me that for a light finish pass on my machine a sharp HSS tool provides a very good finish.

 

[mikey]

Personally I think the hss over carbide is much over preached there are very few times when hss is better than carbide.

It might surprise you that the VAST majority of hobby guys use carbide, not HSS. It's true. For a hobby guy, and especially for new hobby guys, slapping an inserted carbide tool holder into a QCTP is far easier than learning to grind a good HSS tool. Some of these guys think that carbide is so good that there is no need to even bother learning to grind a tool. For others, T-15 HSS inserts from AR Warner are the cat's meow, and far cheaper in the long run that carbide. If you haven't tried a T-15 insert for finishing stainless steel, you don't know what you're missing. So, carbide (and HSS) inserts are alive and well in most of the hobby world.

So, lanagos, let me ask you. If you had a Sherline lathe that weighs 35# all in, with 0.08HP and is largely made from aluminum with plastic gibs, would carbide still be the best choice? How about a little 6" Altas lathe with a 1/4HP motor or a 9" South Bend with a 1/3HP motor that gets up to maybe 1800 rpm, max? Even larger but older lathes that are more rigid often have a max speed under 1600 rpm or less. And then there is the fact that for hobby guys, most work pieces will be under 1" OD or often made from Aluminum. Is carbide still always superior? I suggest it is not and I know you know it, too.

When you have a rigid machine with big HP and high spindle speeds, carbide is clearly the best choice but this is rarely, if ever, the case in a hobby shop. Again, carbide is still tops amongst hobby guys but there are some of us who know how to grind decent tools from HSS and maybe we talk too loud, I dunno'.

 

[Ianagos]

It might surprise you that the VAST majority of hobby guys use carbide, not HSS. It's true. For a hobby guy, and especially for new hobby guys, slapping an inserted carbide tool holder into a QCTP is far easier than learning to grind a good HSS tool. Some of these guys think that carbide is so good that there is no need to even bother learning to grind a tool. For others, T-15 HSS inserts from AR Warner are the cat's meow, and far cheaper in the long run that carbide. If you haven't tried a T-15 insert for finishing stainless steel, you don't know what you're missing. So, carbide (and HSS) inserts are alive and well in most of the hobby world.

So, lanagos, let me ask you. If you had a Sherline lathe that weighs 35# all in, with 0.08HP and is largely made from aluminum with plastic gibs, would carbide still be the best choice? How about a little 6" Altas lathe with a 1/4HP motor or a 9" South Bend with a 1/3HP motor that gets up to maybe 1800 rpm, max? Even larger but older lathes that are more rigid often have a max speed under 1600 rpm or less. And then there is the fact that for hobby guys, most work pieces will be under 1" OD or often made from Aluminum. Is carbide still always superior? I suggest it is not and I know you know it, too.

When you have a rigid machine with big HP and high spindle speeds, carbide is clearly the best choice but this is rarely, if ever, the case in a hobby shop. Again, carbide is still tops amongst hobby guys but there are some of us who know how to grind decent tools from HSS and maybe we talk too loud, I dunno'.

Mikey I have large machines and run high horsepower with big tools but that’s not always been the case. I started with a Chinese import 9x20 lathe and I ran those small Chinese lathes for some years. Yes they were lacking of rigidity and they had the tiniest little belt driving the spindle. But carbide could still be used.

Even With negative rake tooling I can take small .003” doc but once you move into high positive rake tooling like ccgt inserts and the like you can take whispers off.

Carbide as a material does not take any more horsepower to cut than hss. It’s because most of the common and cheap surplus available insert geometries are not meant for finishing.

Next time I see a cheap small import lathe I’ll have to buy it just to make some videos proving that I’m not crazy.

Also I’ll leave this picture here about finishes in stainless with carbide

 

[mikey]

Yeah, I know inserts work on small machines but they work better at the speeds they were intended to work at and most of us cannot get that speed, which is my point. I think hobby guys should be able to use both carbide and HSS; one will almost always be better for a given job than the other but to categorically say that one is better all the time, no, I don't buy that.

 

[Ianagos]

Yeah, I know inserts work on small machines but they work better at the speeds they were intended to work at and most of us cannot get that speed, which is my point. I think hobby guys should be able to use both carbide and HSS; one will almost always be better for a given job than the other but to categorically say that one is better all the time, no, I don't buy that.

Yes my small lathes would all do 2000rpm and that is plenty enough speed to do pretty down to 1/8” my American pacemaker only does 1500rpm but I haven’t had any problem getting along but it’s a little more rigid than those Chinese lathes were.

My turning center id rarely run over 2000rpm due to some mechanical issues. And I turned much smaller diameters on that then I have ever done (very well) in my manuals.

Also I agree that hss is still useful but not as necessary as the guys who come on here and say you need to learn to grind hss tools.

I can but haven’t in years ground hss. Once I discovered carbide I stopped listening to those that said grinding hss was going to be necessary.

The nice thing about hss is the ability to grind custom tools whenever you need.

Anyways I just want to let people know hss is not the only way. And especially for a new guy getting $20 of carbide inserts with a holder will get him turning instantly and if they are careful last a long time too.

Mikey I don’t know your experience with insert tooling but there’s tons of different stuff out there.

 

[Jim F]

I was just asking due to my grinding skills need honed, I have a lifetime of HSS bits from an estate sale.
I have no problem using them , I just have somethings in mind to do as soon as the weather allows, and the grinding will take some time to get the hang of.

 

[mikey]

Anyways I just want to let people know hss is not the only way. And especially for a new guy getting $20 of carbide inserts with a holder will get him turning instantly and if they are careful last a long time too.

Mikey I don’t know your experience with insert tooling but there’s tons of different stuff out there.

I'm not arguing with you in the least! I've been using carbide inserts for 35 years and for the ones I use, I know them pretty well. I agree that inserts will get the new guy going quickly and I'm on record here saying the same thing. I also agree that HSS is not the only way, and I'm on record for that, too.

With that said, I am not willing to concede that carbide is the only way or the best way to go for everything. I know for a fact that on my lathes, a good HSS tool will cut deeper and also cut finer than any carbide insert I've used for most materials I use in my shop. For example, I cannot take a 0.050" deep cut in mild steel on my little Sherline lathe with a CCMT finishing insert or a CCGT-AK insert, but I can take that cut with my HSS tool without chattering and leave a good finish behind. That same tool will also take a 0.0005" cut easily with almost no deflection, something no insert will do in my hands. My Emco lathe cannot take a 0.20" deep cut in mild steel with those same inserts without chattering unless I gear it down a step but it will with my HSS tools. This is why I say that a good HSS can enhance the performance of smaller lathes.

It has long been my position here that both HSS and carbide have a place and I maintain that we should learn to use both. Towards that end, I've done all I can to help our guys learn to grind tools so they have the option. I've also tried to share what I know about carbide tooling (clearly not as much as you, I'm sure) in multiple threads here. Tooling isn't just an either/or; it is a both/and.