Indexable tooling confusion

Hi all

It may be just me but I find all the permutations of indexable tool holders and inserts very confusing ( may be my age ), I need to make something quite large well large for me anyway out of brass , I usually only make brass parts using the hand graver but as the part is to large and I have the Myford equipped with the Rocketronics ELS I thought I may as well use it because the part I need to make is a radius, anyway the problem is I have been using a glanze SCLCR holder with

CCMT060204 inserts and been getting brilliant results on steel and stainless but I need an insert with negative rake for brass and I think aluminium, can I get an insert with negative rake to go into the holder or do I have to buy a different holder.I had been using eccentric engineering tool but I found that although it was good for most things when using the ELS it was okay for the first few cuts when it started getting more than 2 mm of shoulder it would jam and stop the lathe also damaging the part in the process so I sold them and I don’t get any problems with the above tool and getting a superb finish.

Negative geomerty really applies to HSS tooling, the CCGT inserts are positive and cut brass and other non ferrous materials very well. Try ARC or APT These will fit your existing holder

The normal CCMT inserts work fine on brass. For aluminium use CCGT inserts. They are polished and have a large positive rake. With aluminium watch out for the swarf bird nesting.

Andrew

That’s quick and good news thanks for your replies.

Dell

In my experience ccgt can provide a very fine surface finish on most materials, including brass. However, the large positive rake means that if you try too take too deep a cut they can grab and pull themselves into the cut with unpredictable results.

Rod