"Cheap" inserts that *work*

[RaisedByWolves]

Okay, I'm not into insert tooling on the lathe, but I do own it an occasionally use it. One area where I do prefer insert tooling is on certain ops in the mill, like face milling. I stick to Kennametal and Iscar, and they last forever, even on hard interrupted cuts. Since the thread is about cheap inserts, I think price is more about sourcing than brand and origin. I've never bought domestic or tier 1 import inserts (Israel, Sweden) at retail, just NOS in lots or partial boxes as they come up on fleabay. The prices have gone up steeply on those as individuals (and I assume small shops) have turned to eBay as a lower cost alternative to the MSC catalog, so the competition is making it harder to nab popular sizes (I mean you, CCMT), but I'd rather search and pay a price that has a bit of a pinch than deal with cheap inserts that chip and scrap work all to easily. It's so hard to tell one rainbow-colored insert from another when you can neither trust nor verify the quality from lot to lot. With the ISO 9001 major brands, you know what you are getting without surprises.

I hear what you're saying, but most of the cheap inserts Ive bought in the last few years have been equal to or better than K-Metal.

20yrs ago this was far from the case. I wish I would have saved those inserts just to show what they were like. They may have been OK in a Mill taking millscale off of freshly rolled hot roll in a high HP machine, but they were so crude you could forget finish altogether.

The chineses inserts are not certified, sure, but at $1 each Ill happily buy a box of mystery inserts over ISO certified, and then stock up on the ones I like. I look at it this way, if I come across some turds, it is what it is. If I come across a bunch of turds Ill paddle in a different direction.

If I were running production shop it would be a different story.

0.02c

ETA: As far as running a production shop goes, I think what Im seeing with these inserts is due to the chineses using their own inserts for so long they now demand quality from themselves and realize putting out cheap crap to the home shop community will not do them any good.

 

[RaisedByWolves]

That's just it. There's a certain point where it all starts to get a bit weird...

View attachment 494460View attachment 494461View attachment 494459

Fookin ell, I laughed too hard at this and pulled a lung.

There is no law that says you can not regrind inserts. I have been doing it for over 60 years. I have no preference on carbide or hss tools. In
a production shop you want speed and use tools made for speed. And changing an insert is the way to go. On CNC machines changing an insert is quickest way to go. Time is money. You have to pay off that machine.
In a home shop who cares if it takes 1 minute or 10 to change a tool?
When I was doing thousands of the same part every month it matters how fast you can load a part in the machine. Time is money.
Jim Sehr

Ive ruined insert holders at work grinding inserts and I'm not proud of it.

If they would just buy us what we need and keep it on hand this wouldn't be an issue. I've even resorted to using the carbide insert backer on top of the insert backer to make something to use in a pinch.

If our lines go down it cost (And this is an old figure) $10K per hour of lost profit, so when ****s broke they want it fixed NOW and dam the torpedo's. Ive been a hero and a zero doing work like this and have done things to inserts that should rightfully never be done to a component of any mechanical devise, in the name of expedience.


Its literally sometimes break $50-100 worth of inserts in an hour or lose $10K the next hour and send 1300 people home without a full paycheck.

But, eh, no pressure right?


This is my new favorite toy. Total cost for the holder and a pack of G inserts was $28?

.200 dia cut in A-2 tool steel. I'm flicking the feed off and back on to break the chip and Im getting great tool life with these. Probably turned 4-5 parts, all hogging cuts as thats what I use this for, and I haven't needed to turn the insert yet.

 

[pontiac428]

Full disclosure, I haven't tried a cheap insert in at least 5 years. Chinese production has put a lot of competition out of business in that time, and they are indeed improving. The cheapies I've tried were, for the most part, as tough as a box of Saltine crackers. There are a number of factors to consider in what causes an insert to fail, so don't misread my point, but when an insert does chip, it has a nonzero chance of scrapping your part. That's more my issue, the introduction of the possibility that you'll hit a whammy, draw the old maid card, or roll a crap. And the latter really stinks. Like facing a rifle bolt and breaking an insert on the interrupted cut at the ejector bore, d'oh!
I overcook the HSS more than I care to admit when I don't calculate my surface speeds, but it doesn't cost me the re-making of a part. I just hone the tool, dial back the RPM, touch off, and move on. I guess this just makes me a contrary Mary or a negative Nancy. Whinging about how I don't like inserts isn't much of a contribution. But the attraction of cheap inserts is a double mystery to me, once for insert tooling in manual work, and twice for the price of inevitable failure.

 

[GeneT45]

Funny you mention that - and funny that you blame cheap inserts. Every insert is going to fail at some point - import or brand name. I do cut my bolt faces, etc with HSS, and HSS, being tougher, tends to wear more than fail, so it's a good fit for the task. But the question at hand is inserts, and I've found more than a few that seem equal to the premium stuff - and quite a few more that are equal to the aforementioned soda cracker...

I have yet to have an insert (import or domestic) actually ruin work, so it's typically break a tip / edge, replace and move on. I'm a big HSS guy, but that's not what this thread's about, so I'll save that bit for another time...

GST

 

[Ischgl99]

I hand ground all the tools to make this part. If I didn’t learn how to hand grind hss and carbide . I would have had a hard time trying to find an insert to do this part.

There is certainly a place for hand ground tools. I grind some tools by hand when the need arises, but I am not going to do that when inserts work well, and can be found fairly cheap, unless as you point out here, it would be difficult to find a tool to turn that. Sure I would be better at grinding tools if I did it all the time instead of using inserts, but my needs for custom ground tools is not that big, so I’ll stick with inserts.

 

[David2011]

This is my new favorite toy. Total cost for the holder and a pack of G inserts was $28?

.200 dia cut in A-2 tool steel. I'm flicking the feed off and back on to break the chip and Im getting great tool life with these. Probably turned 4-5 parts, all hogging cuts as thats what I use this for, and I haven't needed to turn the insert yet.

Some of you know that I moved up from a 1 hp 11x26 Chinese lathe to a 3 hp 3 phase 13x40 Taiwanese machine a few months ago. The machine is more capable than I am. With the Chinese lathe I was happy with an .030" DOC on the right materials. With the more powerful machine I'm having to grow "bigger ones" to work up to the depths of cut that it can take. It's a little intimidating to look at the tool position and say to self, "I'm really going to take that deep of a cut?" Then nothing bad happens when I do; it just takes time getting used to doing it.

I started out with HSS and still find it immensely useful. I grind form tools fairly frequently but I also appreciate believing that tool geometry with carbide inserts is not a problem when something isn't right. Then I change to another insert of the same shape and everything gets better.

I want to thank those of you that helped me when I posed the same question several months ago. I was asking about the biggest bang for the buck in inserts and many responses were to pony up and buy good stuff. Thanks, gentlemen. You weren't wrong. There is some room for "almost top of the line" without breaking the bank but better has usually been, well . . . better.

ETA: As far as running a production shop goes, I think what Im seeing with these inserts is due to the chineses using their own inserts for so long they now demand quality from themselves and realize putting out cheap crap to the home shop community will not do them any good.

I think there's a lot of merit to this as well. Within even the last year something has changed. I'm getting far less breakage and longer life out of the no-name Chinese inserts that come with tool holders using the same Chinese lathe that I was using 2 years ago. I was breaking inserts frequently without an obvious reason, sometimes within seconds or minutes of installing them. More recent inserts of the same shape and size are lasting for weeks of 10-25 hours/week of part time use.