Problems with newly purchased indexable tip cutting tools.

Hi Jason. Scrolled down to the bottom of the ad and he is showing a dcmt [with dimensions !!] next to the holder for cc, very strange that one .

Some botched up picture of a tip that is not designed to fit the holder shown... SCMC holder + DC** tip... I don't think so... unknown brand ... & look at the price... warning bells chaps

George.

Agh!

Even I wouldn't do that...

Neil

What is the difference between CCGT 060202 and CCGT 060204 ? Which is better for brass ?

Brian

Different tip radius, 02=.2mm, 04=,4mm and so on.

Text below copied from an earlier post may help you.

First letter denotes insert shape, C=80deg Rhombic, D&K=55deg, R=Round, S=Square, T= Triangular, V=35deg.

Second letter denotes clearance angle. B=5deg, C=7deg, E=20deg, N=0deg, P=11deg.

Third letter denotes tolerances on thicknes and inscribed circle size, M denotes +or- 0,13mm for thickness.

Fourth letter denotes type, A,N,Q & W are flat top, G,M & T tops are shaped to provide cutting clearance and chip breaker.

First 2 numbers denote cutting edge length, 06=6mm on C shape insert, 07=7mm on D shape insert.

Next 2 numbers are insert thickness, 02=2.38mm, 03=3.18mm, T3=3.97mm, 04=4.76mm

Next 2 numbers are for nose radius, 02=0,20mm, 04=0,40mm, 08=0,80mm, 12=1.20mm.

The ISO codes sometimes have additional info such as PF for finishing or PR for roughing.

Emgee

Edited By Emgee on 15/10/2016 10:01:44

On the small stuff you do and your light lathe get the 060202

Thank you very much for that information. I have just ordered a box of 10X CCGT 060202 tips from Hong Kong.

What should be used for steel : CCMT 060202 ?

CCMT is best for steel other than stainless.

I've discovered that, on tough materials (carbon steel, stainless), I get poorer finish when the cut depth exceeds the tip radius with a CCMT tip.

Neil

Brian

Carbide inserts are manufactured in several different grades, each with it's own dedicated properties and therefor more suited to cut some materials than others. Most will cut all materials with varying results and also some are better for finishing than roughing but nearly all are available in the various shapes used including your C 80 deg toolholder. Check online tool manufacturer's catalogues for more detailed information on Insert Grades.

Emgee

Brian, the CCGT will also work well on small steel parts but a few of the CCMT will be more durable for larger steel items

I will order a few of the CCMT and keep them for steel parts.

There is holder available for CCMT0604 tips which allows the 100 degree corners to be used, when the 80 degree ones are worn/chipped.

I think that Greenwood Tools sell them in UK.

I use one for roughing, since it uses tips which would otherwise be scrapped

Howard

Edited By Howard Lewis on 15/10/2016 18:26:07

This may sound a bit daft but have you tried just using an autofeed cut rather than hand turned? I use some carbide insert tools that cut horribly when fed by hand but are perfectly finished on self cut.

Michael W

If Brian has ordered the tips Neil linked to earlier I think he will find that they are ok on steel but may tear leaded free cutting.

On a mini lathe I have had vibration problems on steel with the triangular ones I use on deeper cuts. Don't think that it's down to the rad more the rake on them,

However if as I believe Hopper sorted out the rear gib strip it might not act up at all.

I had no problems with the triangular ones same style of tip that Brian initially received but black GP tips on brass but that was on the boxford. These were probably the cheapest Chronos could get their hands on - with a coating. The ones on RDG's 16mm boring bar, gold coating were fine on brass too. The angle the end is set at is stupid though.

Adding to Michael W's comment feed rate can make a hell of a difference. The one that usually causes problems is too fine. A small change can make a big difference. Too fine a cut as well at times that really needs a faster feed.

John

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Edited By Ajohnw on 15/10/2016 20:03:44

What angle is the tip set at John? I was looking at these but if they are less than optimal I may just look elsewhere. I've a couple of smaller bars I made and set the tip at about 7 deg pos to prevent rubbing, they work well, I've seen commercial ones set between 10 and 12 deg.

The auto feed is probably a little bit worse than manual feed.....it is certainly no better.

My experience with people who use indexable inserts is that as they do not understand the technology behind them and consequently do not run them at sufficiently high speed. they need to generate heat to become effective. In view of this I always advise that they increase the speed and feed. One then has to understand the tip technology. There are various substrates for different materials hence why there is such a variety of inserts available. I currently have two tool catalogues both of which are about 3 inches thick which demonstrates the variety available. I would therefore advise the use of reputable makes and be guided by their tables for the cutting data. This can be found on most web sites.On the question of inserts you see at the shows inserts loosely displayed and rubbing against each other. I would advise never to purchase such items, one only has to look at quality manufacturers who sell them in boxes of ten each in its own compartment. Even when I have requested a sample insert for trial purposes this will always be sent in its own box.This advice would also apply to other items like files and reamers and milling cutters.

Ken Price

That's a bit simplistic Ken. In some cases, particularly low carbon steels, you do indeed need high surface speeds to get a good finish with insert carbide tooling. On some other materials it is less clear cut. Again with feedrates the finish obtained depends to some extent on the material. What you do tend to get when using the higher feedrates is proper chip breaking rather than great long snakes of swarf. They look pretty but are awkward and dangerous.

Andrew