Quality indexable lathe tools

Hello all.

After reading through this thread, http://www.model-engineer.co.uk/forums/postings.asp?th=116474 , I want to get some recommendations on which particular indexable lathe tools for a home lathe (Myford ML7 in my case) to cut the usual array of metals.

I must stress that I am a newcomer to metalwork, and not an engineer by trade, so the acronyms etc are double Dutch to me e.g. "CCMT inserts".

Finally, I am only interested in quality tools (without being industry leading!), having been disappointed with prematurely bought imported tools in the past.

You can decode most turning insert designations and/or choose insert shapes here -

http://www.carbidedepot.com/formulas-insert-d.htm

I can't help you on brands as I do go for major manufacturers.

Nick, you've linked to this place previously. The problem is that carbide depot is American, so the numbering is in imperial units yet the rest of us are metric. Trying to understand what eg a CCMT060204 insert looks like isn't going to work out so simple....

Sorry I would link to a metric site but I'm caught up right now.

For hobby use I don't think you would go too far wrong buying a set from any of the suppliers advertising on this site. Buying randomly off ebay and the like is more risky

For my mini-lathe I used Glanze holders; they were fine. When I bought a bigger lathe from Warco I got an unbranded set from them; it also is fine.

Replacement inserts requires a bit of care, the cheap inserts I bought at an Exhibition were a disappointment, but the same spec from Arc were good.

Inserts make life easy for the beginner because you don't have to worry about sharpening. Apart from the learning curve, HSS is well worth the effort. The ML7 is a 70 year old design with a relatively low top spindle speed. As Carbide inserts are at their best worked hard at high-speed, they don't really shine on older equipment. For hobby use, I don't think you're missing much by not having a fast lathe. After learning on this forum how to sharpen HSS, it's what I tend to use most these days. This is even though my lathe has the sort of oomph preferred by inserts.

The world of 'CCMT' can be quite bewildering because it's a system that codifies a wide range of inserts for different purposes. Most of them you will never want to use. It becomes simpler to navigate the system when you have a set of holders because these only take one size of insert, which narrows the field. Once you have a known set of holders, you can ask about inserts for them here.

Dave

You will, I'm afraid, have to have a little understanding of the designation codes. Many of us use the CCMT style of insert as a good general purpose shape for both turning and facing. Something like this I favour the 8mm size for a Myford. The JB holders are good value, I don't see any point in getting holders from the premium brands for amateur use. The final figure at the end of the the stream of numbers for the inserts is the radius of the tip of the tool and I would recommend getting 08 for roughing and 02 for finishing in steel. The CCGT tips are specified for aluminium and stainless steel. They are very good also for fine finishing mild steel but are very delicate so best saved for a really fine finish. The CCMT/CCGT tips are very versatile and can also be used in boring bars of various sizes. They will give you a good start. After gaining a bit of experience you may find that you need other shapes for particular purposes.

As for brands for the tips - I find those sold by JB to be good quality but Sumitomo, Sandvik and those sold by APT all have good reputations.

I thought I ought to respond fairly quickly before you are told to grind HSS or get a tangential toolholder (which I'm sure are good and worthy sentiments, but not what you asked )

HTH,

Rod

Doh! too late - see what I mean?

Edited By Roderick Jenkins on 06/02/2017 12:42:19

Guilty as charged! I should have made it clear that I happily used inserts for 3 or 4 years before picking up on HSS, and wasn't trying to put choochoo off. By the way, assuming it's the same Roderick, 'Density in the Kitchen' ticked all my boxes - very interesting.

Dave

All good info re CCMT shape inserts but it is fine for turning and facing as long as there are no acute angled parts on the work into which the tip won't go, you can then go to a DCMT which is less included angle and will turn quite intricate shapes. VBMT insert are the most "pointed " but available with a range of tip radius from .20mm (02), 04, 08, 12.

Link below to good selection which you may find helpful.

APT inserts and holders /**LINK**

Edit: I now see the furthest right insert on the top row is a DCMT shape not CCMT as labelled.

Emgee

Edited By Emgee on 06/02/2017 15:17:40

Alidirect (Hong Kong) the choice and price is unbeatable, best to look at all the buying choices as the same tooling sets appear several times from different suppliers with different prices and shipping cost so its a case of finding the best deal. I bought a couple of sets of straight turning tool holders and boring bars a few weeks ago and can't fault them.

This is one of my favourite insert tools.

**LINK**

The problem with inserts suitable for hobby lathes is that the inserts aren't always that durable. Used as your only tooling you could end up poor quite quickly. I therefore back up my insert tooling with a Tangential tool for general work.

I would be choosy and buy the best cutter holder within budget. You can source your inserts from any of your choice, but if the holder is not a good fit to the inserts, is flexible, slightly the wrong angle, poor threads in the screw hole, etc. you are stuck with it.

At the same time, if you total one - due to inexperience - it can be an expensive lesson!

It really depends on the intricacy of your work. Bigger tools are great for long, straight surface cuts; smaller ones are necessary for those jobs where access is more diffiCU

lt.

I think there must be many more discussion threads on this topic than just the one you have listed. Plenty of u-toob expanation/discussion, too. I expect you will eventually buy a set, then end up buying better ones in the future, or realise they are not always all they are claimed to be.

Edited By not done it yet on 06/02/2017 17:42:11

To echo what Dave wrote, my honest opinion is that you would be best to leave them well alone ( I apreciate this wasnt your original question but I think you may end up coming to this conclusion in time), especially as a newcomer to turning. I say this from experience, and the trusty ML7 wont run anywehere near the optimal speeds that most inserts are designed for. Add in the cost of new tips and the requirement to have specific tips for specific types and grades of metal and for me it becomes more hassle that its worth - with one exception, and that is parting. I do have several sets of index lathe tools but these are for specific jobs on specific materials, and dont see the light of day very often. Best advice would be to buy one general purpose holder and see how that goes as opposed to a full set, half of which never get used anyway - and have a go at grinding your own hss bits, either way good luck and enjoy.

The code is a bundle of letters and numbers each indicating one of the characteristics of the insert, how many corners, what angles, how big, how thick, what radius at the ends, what sort of chip-breaker, what composition of carbide, what coating, etc. Only a big chart with lots of the options is going to help, but I'm sure that such things exist in metric as well as imperial or US units.

What you say 'quality' though, another nest of vipers is involved. To a quality engineer (who ought to know, I suppose) this means how accurately the product matches the specification called for by the designer. And I'm sure that is no help, but it does mean that you need to explain what, exactly, you mean by 'quality' for your needs.

Regards, Tim

Edited By Tim Stevens on 06/02/2017 18:30:01

I have a Myford Speed 10 and rarely use anything other than carbide inserts and they work just fine provided you get decent inserts. There is a lot of cheap rubbish out there and I am sure this is what puts people off using carbide inserts. They try a poor type and get poor results and think that they are not suitable for small lathes. Buy a really good brand like Sumitomo and you won't go far wrong. The sharp edged polished high rake inserts are my favourite and they work very well indeed on aluminium and also steel but you must take care with them as they are easily damaged if you are too rough with them.

These inserts don't need to be run at high speeds to get good results, just experiment to find the best speeds and feeds and don't be put off trying by those that say they don't work: they do work.

Doug

I use CCMT060204 and CCGT 060204 from JB in one of their toolholders.

You do need to work them hard to get good results, but a decent depth of cut is more important than sheer speed - they are not good at the light shaving cuts HSS excels at. This means a bit of planning to make sure your sizing cut is not too light.

I've also found ArcEuros inserts work well, but I've only tried their parting ones.

One oddity I came across recently was some really nasty stainless. The carbide was making it work harden causing poor surface finish and difficulty of follow up cuts. In the end I use my tangential HSS tool but it needed to be kept very sharp - honed after every few runs.

I have a mini-lathe.

Neil

A couple of weeks ago I bought a set of 10mm Glanze CCMT 0602 tools, also bought an 8mm boring bar from RDG as well as a couple of spare inserts.

If I had only used the RDG inserts I would of binned the lot on the first day, they were terrible. The inserts included with the Glanze tools are miles ahead. I also bought some CCGT sharp inserts which are excellent for aluminium and are good for light finishing passes on mild steel.

If your worried about surface finish then yes you do have to take heavy cuts, and you can't doddle with the feeds either. However I'm getting great results using them, even on some 3inch OD EN19T I have, granted I can't take much more than a 30thou cut in that, but after all it's a 0.5hp 40year old myford.

The shapes are the same, I'll use your metric link in future, once you post one :D

This and the next page is quite an easy to follow chart

The RDG inserts might improve if you give them a touch up with a diamond lap.

The Myford at 70 +yrs old(design), in those days many of the model engineers looked at HSS the same way that today's MEs look at carbide, many of them preferred to use carbon steel , I could imagine there are still some.

For general work HSS, carbide for special purposes. Just my oppinion.

Ian S C