Lathe tool insert bits

Ive been looking to up grade my selection of tools bit which are largely old HSS stock and carbide index bits seems the way to go. So do you go for Sandvik Coro? - expensive or cheap chinese?

Whats your preference?

Many years ago at an Machinery exhibition I saw a demo of a ceramic tool tip, cutting 1/4 in from a 2 in bar. What struck me was the speed (around twice normal I think), a single blue swarf curled off it, and the operator invited us to put fing on the tip after he finished adn it was cool, no cutting fluid used and the surface finish was almost mirror

Was I dreaming?

Whats it called?

Cheers

Robin

First question would be whats your lathe as the tips don't work well on a flimsy machine or one that won't allow a decent size cut to be taken.

Also what sort of size work do you mostly do, if its large then it would be best to try and standardise your holders to a large tip like CCMT09.... Though for most of work we are likely to do then the CCMT06.... is OK if you want to use the rhomboyd shape. Then there are parting tips, profiling tips and so on.

I use a mix of tips, Sumitomo, Seco, Kennametal, etc in various tip radii and top rakes.

The majority of my holders are Glanze and seem to work fine for me.

J

Edited By JasonB on 14/11/2012 12:33:49

Sorry pardon I should have mentioned Myford ML7 (too small to maul)

Its coming back to me now, You have to take a decent cut at high speed or they don't work properly, is that right?

No skimming then?

Cheers

Robin

I can happily cut 1/4" from BMS using my Sandvik tips but honestly how often in the home workshop are you going to need to do that? In the other extreem I have taken 0.01mm with my sumitomo tips.

As Jason said Glanze tool holders are well priced, best to pick a single tip size and try to get a selection of tip holders which take the same sized tips.

My preference? Well since I learnt a lot more about using lathe tools and cutting from using my Cowells is an appropriatley ground HSS tool. But I still use tipped tools for nasty stuff which has hard spots in it.

Edit: the 1/4" cut was on a 40mm dia bar on my Colchester Master .

Jo

Edited By Jo on 14/11/2012 13:16:48

Robin, as the tips are not a sharp as HSS they can have a tendancy to be pushed off the work when taking light cuts but some tips are better than others.

I would not throw your HSS out as its useful for fine work and finishing bores but maybe just add a couple of tools for hogging out on large jobs or things like castings that may have hard spots and inclusions.

The tips for Aluminium are worth getting if you work that much and can take a fine cut but the thinner edge is more vonerable.

J

Hi all

Thanx for the tips

So HSS is still ok. Talking of thread cutting, I remember seeing one of these super tool tips doing a 1/2 ins thread on steel bar in one pass. The tool was upside down and cut away from the chuck going in reverse. High speed and mirror finish - scary - but nothing for an auto.

Does anyone try rolling threads?

Robin

"Does anyone try rolling threads?"

yep.. love it...better strength /finish.. fast ..accurate. consistent... but at around £2 k for roll head and £800 a set for rolls not really for the one off... but if you ever need 10 k threads all the same at 1 second per inch at 1700 rpm then nothing like it. (1/2" unf in en16T)...

thread rolling "taps " are available and work great in ali , copper and stainless but you need the specific tap for each material...again no swarf and work hardened thread stronger than original metal....

Edited By jason udall on 14/11/2012 14:39:01

Robin;

For a number of years I was 99% carbide tooling. Great for cast iron, but on other metals, so-so. Maybe the expensive ones I was using are not tuned to the metal turned.

I'm finishing a Worden grinder, and expect to go back to 99% HSS, but we'll see.

Yes, blue steel chips from Carbide are great, unless you are moving the carriage by hand, then your wife/husband wonders what disease you have because your hands and arms are covered in little red spots. (not joking - hot swarf causes little burns).

The Worden will also re-sharpen end-mills, and drills, so I expect it to pay for itself in saved carbide insert costs and endmill replacement fairly quickly.

Everything has its place, and for me, my choices will most likely be different from yours;

Another JohnS.

Yes, so why do so many lathes have the handwheel at the left hand end of the apron?

Russell.

Blame the Americans — it's their favoured design practice! Historically, European manufacturers (including the British) favoured a right-hand carriage handwheel but if they export to the USA, they've had to offer a left-hand option.

Joe

Edited By joegib on 15/11/2012 05:33:44

A number of people seem to have the mindset that carbide tips are no good for smaller lathes and are only good for deep cuts at high speed. This may well have been the case when carbide tips first came to be used in the home workshop, but things have moved on since then.

Old stock bought on fleabay may prove to be disappointing but there are excellent tips out there that have good positive rake and sharp edges and will perform very well on a smaller lathe. I use a Myford Speed 10 lathe (a baby Myford) and get excellent results with decent carbide tips even with finishing cuts. If you look at the edges of a good quality solid carbide endmill you will notice that the carbide can be very sharp and this sharpness is obtainable on a carbide insert for lathe work. The downside is that you have to be careful not to chip the edges which are quite vulnerable.

Doug

I use sumitomo tipped tools on my Cowells, tips/tools that I first brought 18 years ago for use on my Hobbymat.

Yes the same 10 sumitomo tips I originally purchased with the holders have lasted that long, I think I have "worn out" two edges over the years so have another 18 edges to go, I expect these remaining ones to last my lifetime. Other cheap tips seem to last a month or so. I abuse them all with the same enthusiasm so not all tips are the same. But I use them less than I used to, since I became converted to HSS.

Jo

Edited By Jo on 15/11/2012 10:10:07

Edited By Jo on 15/11/2012 10:10:29