Carbide insert crash course?

[LVLAaron]

@xr650rRider I'd love to see your upside down threading setup.

 

[Ischgl99]

Something to consider if buying name brand inserts, Kennametal sells their inserts in packs of 5, that’s a bit easier on the wallet.

I have been using a CCGT HP for high positive insert on steel in a KC5010 grade and am happy with the performance. I also recently got some UF for ultra finishing in a CCMT, also in KC5010 and at some point will do a comparison to see which I like better. Something to look at for aluminum is an H01 grade, it does not build up on the edge since it is uncoated. The silver colored inserts you have may be that, my Korloy H01 inserts are also silver colored.

Since the GT style inserts don’t tend to last as long as MT style due to the sharper cutting edge, I prefer to use a more robust insert for roughing and then switch to my GT inserts for finishing. I leave enough for finishing so I can get two passes to make sure I am on size when changing the insert.

Travers has sales on inserts fairly frequently, usually not the ones I am looking for at the time though. A place that has been recommended on various forums for years is latheinserts.com, the owner used to work for Kennametal and is a good resource for quality inserts at good prices. I haven’t purchased inserts from him yet, but have bought tooling. I plan on trying some of the value ones he sells when I start getting low.

 

[LVLAaron]

Something to consider if buying name brand inserts, Kennametal sells their inserts in packs of 5, that’s a bit easier on the wallet.

I have been using a CCGT HP for high positive insert on steel in a KC5010 grade and am happy with the performance. I also recently got some UF for ultra finishing in a CCMT, also in KC5010 and at some point will do a comparison to see which I like better. Something to look at for aluminum is an H01 grade, it does not build up on the edge since it is uncoated. The silver colored inserts you have may be that, my Korloy H01 inserts are also silver colored.

Since the GT style inserts don’t tend to last as long as MT style due to the sharper cutting edge, I prefer to use a more robust insert for roughing and then switch to my GT inserts for finishing. I leave enough for finishing so I can get two passes to make sure I am on size when changing the insert.

Travers has sales on inserts fairly frequently, usually not the ones I am looking for at the time though. A place that has been recommended on various forums for years is latheinserts.com, the owner used to work for Kennametal and is a good resource for quality inserts at good prices. I haven’t purchased inserts from him yet, but have bought tooling. I plan on trying some of the value ones he sells when I start getting low.

I'll take a look at Tavers and that link you shared. I guess the hard part of looking for these is if you don't know exactly what you want you aren't going to find it easily. At least @ MSC. There are 40 different CCGT inserts that all look wildly different if you read the description.

 

[Batmanacw]

Go on Ebay and look up CCMT32.51 Mitsubishi grade VP15TF. You can find them for well under $2 each shipped straight from China. They are excellent for very little money. I'm sure there will be a dozen guys telling you that you must pay a dozen dollars per insert but it simply isn't true.

Buy a box to try and then you'll order another 10 boxes immediately. Shipping is slow but it does come eventually.

CCMT21.51 is the smaller insert commonly found on boring bars.

I rarely find myself needing the larger radius like CCMT32.52 or CCMT21.52.

I also recommend CCGT inserts but buy quality on those. The Iscar, Walter, and Tungaloy inserts are excellent.

The Iscar have the sharpest high positive inserts I've seen. All three are excellent on Stainless and Titanium.

 

[xr650rRider]

@xr650rRider I'd love to see your upside down threading setup.

You need to watch Joe Pieczynski and make yourself a simple tool to make sure all your insert tools are on center of your machine.
Also you'll need a spacer on tool holder to be able to get high enough to run upside down.

I use this tool most of the time for anwhere from 13 tpi up to 40 tpi. Cuts very nice threads using cheap inserts. You use a 16IR or 16EL insert for external thread running tool upside down. For the internal threads (tools are shown a couple of posts below), you use a 16ER insert on the tool on backside running in reverse away from chuck. You can set the sockethead screw in aluminum spacer to set height of tool. Screw has threadlocker on it and once set, it doesn't move.

I don't use the compound and plunge straight in. Using DRO, I zero out on thread start and move back to this position every thread pass. Might start off plunging .020" on diameter and reduce as thread get deeper. You can even thread a barrel without a thread relief using this method as well. Your starting thread from dead start with tool bearing on barrel but a couple of spring passes at end and threads come out great. When your screwing on a $1600 action, they better.



Flipped over



I've also have these but rarely use all setup upside down for threading away from chuck.





View of spacer and socket head set screw on back of toolholder.

 

[xr650rRider]

Simple tool made from Joe's video for setting tools on center. Made from 1.25" OD 6061 AL
KISS

 

[xr650rRider]

Left hand internal threading tools. Run lathe in reverse, tool on backside, thread away from the chuck.









Micro 100 carbide 2 left hand threading, 1 boring. All bought on Ebay.

 

[Ischgl99]

I'll take a look at Tavers and that link you shared. I guess the hard part of looking for these is if you don't know exactly what you want you aren't going to find it easily. At least @ MSC. There are 40 different CCGT inserts that all look wildly different if you read the description.

Each of the inserts are a bit different for particular purposes that for the most part are not that important for manual machinists. After reading David's book, you will have a better understanding of the differences and can make a more informed choice. I would avoid trying to educate yourself from catalog listings at places like MSC, that gets confusing very fast unless you know what you are looking for.

It is overwhelming with the number of choices out there, and here you are going to get dozens of recommendations for everyone's favorites. I use Kennametal mostly because I can get packs of 5, so I downloaded their grade and chipbreaker charts and started looking at the differences. Selecting an insert is easier for me by eliminating insert styles and grades that obviously would not work for me, so then the choices are much smaller. The ones that say things like high removal rates and high speeds, probably will not apply to us, so I scratch them off the list and focus on the remaining ones. The KC5010 insert grade from Kennametal is more a general purpose grade for slower machines and why I am using that one.

Give Lathe Inserts a call and tell them what you have and what you want to do and ask for a recommendation, they will point you in the right direction. I have never heard a bad experience with them.

 

[xr650rRider]

Cheap solid carbide 8mm OD boring bar that has become my favorite. It's possible to have a lot of stickout without chatter.
You'll notice I run all my boring or threading tools in a boring bar holder Aloris BXA-4D. I make bushings out of 12L14 and put in set screws. They are bored for a snug fit and actually tightening the bolts on the toolholder actually locks down them down without the set screws.

 

[Watchwatch]

A Micro 100 internal threading tool is a really good option. A $20 tool will handle basically all internal threading in the hoppy shop when combined with taps for smaller holes.

And the cheap CCGT inserts are amazing for what we do. A must buy.


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