What inserts do you like and why?

[VicHobbyGuy]

I'm just a hobbyist also and have had good luck (maybe ignorance is bliss) from inserts from Aliexpress and banggood. They are radically so much cheaper than name brand ones that I'm okay taking a chance on the quality. Someday I might try the expensive one but right now I don't think the inserts are my weakest link.

As the saying goes: "That makes two of us!"

Here's what I've been using lately for DCGT inserts:
https://www.aliexpress.com/item/4001128930528.html?


$10 for 10 inserts, including shipping.
I checked on the DGI website and the cheapest equivalent I saw was $17 EACH + taxes +shipping.
Fortunately Sandvik doesn't seem to make insert tools small enough to fit the OXA holder on my lathe, so I wasn't tempted by the $200 insert holders they produce.

 

[Susquatch]

Most folks here seem to be serious and full time (?) machinists, in spite of the forum name. I'm just a hobbyist, so paying 2x what my lathe cost for a couple of toolholders and 2 packs of inserts would be silly. I make enough mistakes - both buying the wrong tools and then using them improperly - that I would never get 15 times the life out of a 'big name' tool vs something cheap from China. And, with minimum orders and shipping charges for the 'name brands', it is a factor of 15 or more in cost differential. I'm not making critical parts - just stuff for around the workshop and some little engine models- all just 'practice' and learning stuff.
As I said, different (but perhaps parallel?) universes.

@thestelster You use the same type/shape insert for every cut on every material- CCMT for everything, same tip radius and geometry, or just the same "grade' (quality)?

Boy, a lot of posts to reply to! That's what I get for spending the day out applying nitrogen to my corn......

No worries @VicHobbyGuy, I really do believe that the vast majority of members here really are hobbiests. I certainly consider myself a hobbiest. I also think we hobbiests all appreciate the views and help we get from the full time machinists even if we can't always afford to use what they use.

When I started this thread, I wanted to get a full spectrum of input from everyone from beginners to pros. Those needing or wanting that information and advice will choose what they liked based on all the many factors that are important to them. Cost being a big one for me too.

At some point, I will share my own favorites, some of which may already be obsolete given some of the great advice I've already seen here.

So ya, it's all good.

 

[Susquatch]

@thestelster - Our Sandvik dealer in Calgary ignores you for any orders less than 1000$, and treats you poorly for orders less than 2000$. The barrier to entry here is just too high. I've tried to compare Sandvik to Kinnemetal 3 or 4 times in the last 40, but no go.

This is just sad.

Almost all my indexable tooling and inserts are Sandvik. And I get them from DGI Supply in Oakville, they use to be DoAll. Sandvik tooling is pricey, but they are extremely well made, and last a lifetime. The inserts are sold in packs of 10.

A few years ago (pre covid) I asked my local supplier (Varco Industrial Supply) if they would consider stocking and selling smaller quantities of inserts than 10. They said they would consider it but only if it was a very popular item. I never explored it further.

I like Varco. They are an expensive supplier, but if I want it NOW, they are only a half hour away. I buy lots of small stuff from them - eg can I have one 5/16 Dormer Drill please? They cater to the farming community and local industry. No big corporations around here. I walk through the door and they all treat me well. I cannot really complain about their high prices. It is what it is.

 

[Susquatch]

Here's how to 'fix' this problem: If you look with a 20X loupe and see this rounding, ge a cheap set of diamond laps and hone then edge SLIGHTLY. Don't mess with the cut angle or remove much material at all. You will then notice significantly less cutting pressure and slightly improved cutting finish (if done correctly, yadda, yadda)

You can turn the cheapest cutter into a better one this way.

If you are lazy, then buy inserts that are ground and recommended to cutting aluminum. They won't have as long a service life in steel, but will cut cleaner and with less pressure than a normal carbide insert.

Two great pieces of advice. I recall you suggesting that inserts could be sharpened before. This is a great place to remind us of that. I must give that a try.......

Btw, I always thought inserts were sintered, not cast. Learn something new every day!

I have some aluminium inserts that I will try too.

 

[VicHobbyGuy]

At some point, I will share my own favorites, some of which may already be obsolete given some of the great advice I've already seen here.

I'm looking forward to it! @gerritv gave some recommmendations which I appreciated. But generally folks seem to be 'holding their cards close to their vests'. I think it's pretty funny that the only specific insert info (DCGT070204-AK) is from me, since I am by far the least experienced and least competent person here!

 

[Susquatch]

I'm looking forward to it! @gerritv gave some recommmendations which I appreciated. But generally folks seem to be 'holding their cards close to their vests'. I think it's pretty funny that the only specific insert info (DCGT070204-AK) is from me, since I am by far the least experienced and least competent person here!

Ya, sorry about that. It's not about holding any cards to the vest. It's about being old with a memory that never was any good for data points (names, numbers, etc) and getting the facts right. I gotta go to the shop and spend a few hours going through things, trying to remember where I got them, taking pictures, etc etc.

I guess as the OP, I also wanted to let other people have their say first and I had lots to keep me busy in the meantime. But I got my fertilizing done today, so there is a good chance I'll get to it tomorrow.

I may do what @thestelster did and break it into chunks too.

 

[Dabbler]

Btw, I always thought inserts were sintered, not cast. Learn something new every day!

I misspoke. sintered. not cast.

 

[Tecnico]

Here's how to 'fix' this problem: If you look with a 20X loupe and see this rounding, ge a cheap set of diamond laps and hone then edge SLIGHTLY. Don't mess with the cut angle or remove much material at all. You will then notice significantly less cutting pressure and slightly improved cutting finish (if done correctly, yadda, yadda)

Interesting @Dabbler. I had noticed that the edges were not sharp feeling (DCMT) except for the DCGT and thought about dressing them but decided that the tool makers must know what they're doing......I'll have to try it.

I'm kind of surprised at how hard to deal with some of the suppliers west of here seem to be, I just pick up the phone to my local SOWA dealer, Rideout Tools (associated with KAR), and they sell me whatever I ask for in ones & twos which lets me try out a new insert and they don't charge a premium. Maybe they'll ship

D

 

[thestelster]

Most folks here seem to be serious and full time (?) machinists, in spite of the forum name. I'm just a hobbyist, so paying 2x what my lathe cost for a couple of toolholders and 2 packs of inserts would be silly. I make enough mistakes - both buying the wrong tools and then using them improperly - that I would never get 15 times the life out of a 'big name' tool vs something cheap from China. And, with minimum orders and shipping charges for the 'name brands', it is a factor of 15 or more in cost differential. I'm not making critical parts - just stuff for around the workshop and some little engine models- all just 'practice' and learning stuff.
As I said, different (but perhaps parallel?) universes.

@thestelster You use the same type/shape insert for every cut on every material- CCMT for everything, same tip radius and geometry, or just the same "grade' (quality)?

Hi @VicHobbyGuy
Yes, I only use those two insert shapes, CCMT, and DCMT for everything. The DCMT for turning when using a center in the tailstock, and the CCMT for everything else. The coatings on my inserts are optimized for steel, but I use them for all metals, (I can't afford to have inserts with optimized coatings for different materials.) And, I am not a machinist by profession. But I machine in my profession, (I'm a gunsmith.) The insert holders I have are by Sandvik, and are 3/4" x 3/4". And I've had them for at least 20 years, using them almost every day, and will probably last another 20. Pretty cost effective I think. I've attached some pictures of my turning tools, and the exact inserts I use.

 

[thestelster]

When deciding on going carbide inserts, there are many factors that come into play.
-insert shape
-material being machined
-hardness of material
-coatings
-finish i.e light finish to roughing

And machine ability:
-ridgidity
-horsepower
-speed

That is why it is imperative to search out all the information you can about a particular insert you want to use. Companies like Sandvik, Kennametal, Mitsubishi and other top manufacturers, spend so much money on research and development. Go into the website and get that information. Without that knowledge, you're doing yourself a disfavor. I've attached some info from an old Sandvik catalogue that I have, which helped me chose my inserts.

 

[VicHobbyGuy]

Thanks for that info @thestelster . Really useful, and specific. I appreciate the time you took to do the scans and take pictures.

A couple of thoughts:

I haven't found manufacturer's online info very useful - and I've read/scanned that stuff a lot - each time till my eyes glazed over. Not surprisingly the manufacturers are providing info for their primary clients - production/manufacturing concerns, usually using CNC equipment and running everything on a 'time is money' basis - so high speeds and maximum cuts with powerful equipment. Just the opposite of the sort of stuff I do. A carbide insert for cutting steel with a minimum depth of cut of .015 or .025" isn't much use to me. So there's no way around that 'info' problem, other than asking other folks with low power and non-rigid machines (I won't use 'hobbyist' around here any more... ) what works for them in cutting a variety of materials. There are many thousands of 7x lathes out there, so there would be a good small business opportunity for somebody -besides LittleMachineShop- to cater to that market. Even LMS is pretty useless for carbide insert info.

For beginners: The first step is to make sure that the insert holder will fit your toolpost and lathe, and then to make sure that you buy the correct size of insert. I have a pack of size 'ER16' threading inserts to remind me of that; I should have bought ER11s. Not a big loss at AliExpress prices. Some of the 'big name' companies don't seem to make holders with 8x8 mm or 10x10 mm shanks, so that helps to keep the choices in the budget department.

This whole world of machine tool supplies reminds me a lot of the 'bad old days' before HomeDepot made plumbing and wiring suplies readily available to 'amateurs'. Before that, it was inflated prices and being treated like rubbish by the wholesale/retail supply places. Somebody here commented in the last few days that paying higher prices wasn't a problem, since it was tax-deductible (and possibly charged on to a customer?). You can certainly see the results of that situation at Grainger, KBC, etc. ...

 

[Susquatch]

Thanks for that info @thestelster . Really useful, and specific. I appreciate the time you took to do the scans and take pictures.

A couple of thoughts:

I haven't found manufacturer's online info very useful - and I've read/scanned that stuff a lot - each time till my eyes glazed over. Not surprisingly the manufacturers are providing info for their primary clients - production/manufacturing concerns, usually using CNC equipment and running everything on a 'time is money' basis - so high speeds and maximum cuts with powerful equipment. Just the opposite of the sort of stuff I do. A carbide insert for cutting steel with a minimum depth of cut of .015 or .025" isn't much use to me. So there's no way around that 'info' problem, other than asking other folks with low power and non-rigid machines (I won't use 'hobbyist' around here any more... ) what works for them in cutting a variety of materials. There are many thousands of 7x lathes out there, so there would be a good small business opportunity for somebody -besides LittleMachineShop- to cater to that market. Even LMS is pretty useless for carbide insert info.

For beginners: The first step is to make sure that the insert holder will fit your toolpost and lathe, and then to make sure that you buy the correct size of insert. I have a pack of size 'ER16' threading inserts to remind me of that; I should have bought ER11s. Not a big loss at AliExpress prices. Some of the 'big name' companies don't seem to make holders with 8x8 mm or 10x10 mm shanks, so that helps to keep the choices in the budget department.

This whole world of machine tool supplies reminds me a lot of the 'bad old days' before HomeDepot made plumbing and wiring suplies readily available to 'amateurs'. Before that, it was inflated prices and being treated like rubbish by the wholesale/retail supply places. Somebody here commented in the last few days that paying higher prices wasn't a problem, since it was tax-decuctible (and possibly charged on to a customer?). You can certainly see the results of that situation at Grainger, KBC, etc. ...

Lotta truth in them there words......

 

[Susquatch]

Ok, so here is page 1 of Susquatch's adventures. I'm gunna start with knurling cuz it's the easiest.

IMHO, Left is nothing better than junk. Right is nothing to brag about, but it works. Left depends on toolholder pressure against the work. Right is independently clamped down onto the work as the knurl progresses. Left is big bucks junk, right is cheap but effective. Your mileage may vary.

 

[Brent H]

@Susquatch : I have plans coming from England to build this:

I will be taking the left hand unit you show and chopping it up for use as the mounting arrangement and re-purposing the wheels for the unit itself. I also have a couple sets of straight wheels that will go into play. I will, of course, be posting the results of this build.

It is a Hemingway Kits model. - I just ordered the plans - not the materials

 

[Susquatch]

Page 2 of Susquatch's Adventures. Parting.

This is a really nice tool. It was given to me by another member cuz it was a 1 inch tool. I milled the bottom off to fit my BXA Tool Post Holders

Here are the two styles of inserts I got for it.

I didn't get any aluminium inserts cuz aluminium is easy to part with almost anything.

This sucker works. And it works GREAT.

Before I got it, I used HSS with mixed results. Parting conventionally has always been a challenge.

The best solution which has NEVER FAILED ME, it to cut in reverse with an upside down parting tool. You can cut big, small, or whatever. It might make noise but it works. Here are two different types of HSS parting blade setups. Both are setup for parting upside down. I wonder why I have two holders setup that way.......

One is a T-Blade and the other a wedge blade. Both work fine in reverse. But worthy of note is the holder in the left photo. They work fine upside down but totally completely suck used conventionally. My advice is to avoid those adapter holders like the black plague.

One of these days, I will make a super rigid holder for parting. That will be a separate thread all of its own.

Here are a few special grinds I have done to try to part when the part didn't want to part.

 

[Susquatch]

Page 3 of Susquatch's adventures is Turning with Inserts.

When I got the bigger lathe 10 years ago, I bought one of these kits.

Do not waste your money. I only use one of them. The rest just gather dust. IMHO, buy a good one of whatever you think you need. It might cost as much as the whole set, but you will use it.

Here is my favorite insert tool and inserts for it.

I know, it's a trigon WCMT. Seems they are not very popular. But I like it for most insert turning. It has 3 working edges, does a good job of breaking chips and leaves a decent finish. Seems most users like the triangle inserts. I've never tried them, but plan to cuz it's hard to argue with popular.

The other insert tools I use a lot are the round RMCT Inserts.

They leave a great finish and are not very sensitive to feed and speed etc. You can see I use the small one a LOT. They also last forever cuz you can just turn it a bit for a fresh edge.

I will do a separate page for HSS.

 

[Tecnico]

Interesting about your experience with the knurling tools. I have a J.H. Williams tool that came with my Myford and I've been happy with its performance. I haven't tried one of the scissor versions and I looked at all the pinned hinges & joints in them (tolerance/alignment??) plus needing to clamp the wheels onto the work piece and didn't like the look of them!

With a scissor I also wonder how you keep the correct crossover indexing distance between wheels to make the perfect knurl pattern? With the Williams you have to knurl on a diameter incremented in 16ths to get a coherent cross over pattern.

My Williams looks like this (photos from the web):

 

[Tecnico]

One of these days, I will make a super rigid holder for parting. That will be a separate thread all of its own.

@Susquatch I wonder if you had a parting tool holder like this it would make parting with HSS blades more fun? I've used them on several machines and even on my light Myford it gives good results unless I try to do something dumb.

The holders you show don't look like they provide as secure/rigid/support on the parting blade letting it or the holder flex and nothing good comes from that, just ask me....

 

[Susquatch]

Susquatch's Adventures Page 4 - Turning with HSS.

Nobody should be surprised that I really like HSS turning. So many things you can do with it, so forgiving, so easy.

Just learn to grind reliefs, nose radii, and buy decent blanks.

At first I bought small 1/4" blanks cuz they were cheap. But other than a few special applications, I pretty much buy 1/2" and even 5/8" now. My BXA Tool Holders are 5/8.

All the reasons others like HSS apply to me too. I especially agree that learning to grind, understanding reliefs, cutting edges, nose radius, etc etc etc are all very valuable knowledge and skill sets. Despite using carbide inserts a fair bit, I do not advocate inserts for new machinists. There - I said it out loud.

If a new machinist really wants to start turning before grinding, go get a set of these. The quality is great and they work right out of the box. This is probably my 4th set.

And here is what I usually buy. I like 5% cobalt. It holds an edge much longer.

With that, here are a few examples of all the things you can do with HSS. Good luck finding comparable inserts.

This is a special chamfer tool. It cuts a nice radius on the inside or outside of a tube or drilled or bored hole, or on a shoulder.

This is a shear tool. It shaves the surface leaving behind a beautiful finish.

And from left to right are:

A really tough turning tool for bulk material removal. It looks rough and is rough, but the edges are well honed. This thing will take off a lot of metal very fast. Note the heavy top rake to bend the swarf out of the way.

A really sharp pointed tool for getting into really tight places

A front end shear tool

A 45 degree chamfer tool - use forward or reverse to chamfer the edge you want.

A deep inside threading/boring bar combo. (threading coming up soon).

If you look closely at the second and third tool, you will see that they are shimmed to fit the tool holder more solidly and also to put the business end where I want it.

Honestly, I cannot imagine life with a lathe without HSS. It does everything and anything. The tools don't need to be fancy. These are just the ones I use often enough to dedicate a holder to them.

 

[Susquatch]

Interesting about your experience with the knurling tools. I have a J.H. Williams tool that came with my Myford and I've been happy with its performance. I haven't tried one of the scissor versions and I looked at all the pinned hinges & joints in them (tolerance/alignment??) plus needing to clamp the wheels onto the work piece and didn't like the look of them!

With a scissor I also wonder how you keep the correct crossover indexing distance between wheels to make the perfect knurl pattern? With the Williams you have to knurl on a diameter incremented in 16ths to get a coherent cross over pattern.

My Williams looks like this (photos from the web):

I have one very similar made by Armstrong. It worked ok on my old lathe. But not on the new one - mostly because it was intended to be used with a lantern style tool post. I like how both of ours pivot on the work.

The scissor knurler I have works great even though it is really really poorly made. Some things you just can't explain! The problem with the pressure type is the lateral force required to knurl the metal. The scissor type just floats with the work.

I can't wait to see @Brent H s when he gets it done. I suspect that there will be one just like it on my bench soon enough. I really don't like crap even if it does work..... LOL!