Indexable tooling

[Martin of WickParticipant @martinofwick]

Nah,

These are generics.

If you want branded tooling expect to pay 5 to 10 times as much from Sandvik and the like. You can build up your collection by purchasing individual tools from suppliers like APT or ARC etc. They provide the better quality tools so you will pay more accordingly.

[Neil LickfoldParticipant @neillickfold44316]

The GT inserts are a ground outer profile insert. Like an insert for cutting aliminium or copper for instance. Then there are coated GT inserts, these are for stainless steels and Titanium for example. They also work very well on most steels as well for the home hobby lathe. The positive geometry sharp edge inserts (an edge radius of less than 0.02mm, essentially sharp) use less power for the same depth of cut and feed rate. A lot of the pressed inserts, have a dull cutting edge(R0.1 to R0.15), are intended to work differently they. They require the correct speed in general, as they rely on  the plasticising of the material being cut, with the heat going out into the chips or swarf. They will string if the cut depth is insufficient to create a curled chip.

I use inserts that are generally the industry standard sizes. Mainly due to them being cheaper than  the odd sized inserts, and are more likely to be locally stocked by a tool supplier. They also have the greatest range of grades and cutting geometry chip breakers made into the inserts.

For Brass, I like using the Ceramic inserts. Just need to be very careful when approaching the centre of an end face. Being a negative rake angle edge they cut very well and stay sharp for  a very long time .

Some QCTP have holders that will take a 10mm shank tool which works very well in the ML7 lathes.  There are some 8mm shank tools available too, and from the USA is 3/8 shank tool holders.

The DCMT inserts are positive geometry and only have 2 cutting edges. They do have a very big selection though(DCMT11T30X), and there are also bore bars that take the DCMT inserts as well. The smaller DCMT0702X inserts, have 10mm shank holders and work in some of the bore bar ranges.

Common bore bare inserts are the Triangular like the TNMG a negative insert that have positive geometry options, especially in the larger TNMG16 size, which will give 6 cutting edges. So can be used for external turning as well. But the holder will need to the cut on the bottom side to fit a ML7.

The small mentioned cc inserts are great and can be used in bore bars and external holders. So reduces the number of inserts needed for the home shop.

Be careful in buying the small triangular inserts . Some are intended for boring bars only, and do not fit the external holders. Make sure that the inserts are correct for the bar or tool holder. For example, I have a boring bar, and the inserts are too thin. They were cheap though and I didn’t notice that they were the thinner older version inserts. So had to make a 0.8mm shim to use them.  Some are an unusual size as well, so just pays to check.

[JasonBModerator @jasonb]

You mention brands, I gave a couple which are from reputable suppliers but are almost certainly made in China but to a reasonable quality so are in the mid range of price. I’ve used them for at least 15years and no sign of the threads stripping and most have original screws.

The links I gave are much the same as Martin shows except I did not include a chamfer tool, bit of HSS does me for that but I don’t cut a lot of large chamfers, most steam and old internal combustion gets the corners knocked off with a file file applied to the rotating work. Modern IC and the rare bit of tooling gets a chamfer but less than 1mm wide. If you want the odd one then a carbide insert tool can always be swung to the required angle.

You can pay more for known makers such as Sandvic, Sumitomo, etc but they cost more. At the other end of the scale ebay or direct from China you take pot luck as to what you get be it decent that you want or not but cost is less. Same applies to inserts.

One thing you may have missed is that you can get holders for the CC** inserts that make use of the two obtuse corners so you get better use of of the inserts which keeps costs down. These corners are a bit more robust so good for roughing or use on castings.

[patgasParticipant @patgas]

Basket so far, can’t find a 1.5 version of parting as suggested anything I may add to get me going .

[JasonB]

On JasonB Said:

You can pay more for known makers such as Sandvik…

Maybe the OP needs to be made aware that some of the high end brands use non-ISO inserts (Sandvik laydown threading inserts is one example).

It is one of those bizarre things: neither the very top end nor the very dregs conform to standards, whereas everything in the middle does do so.

I wonder if we should split ‘indexible tooling’ into ‘inserts’ and ‘holders’. No matter how cheap an item I have bought, I have never had a problem with the holder (and maybe only once with a chocolate screw). My meanness always shows up in the insert underperforming.

[JasonBModerator @jasonb]

Add a couple of CCGT inserts to your basket, APT sell them in twos for hobby use, these are the ones I use.

APT only do the 1.5mm holders with big shanks, you will probably have to take pot luck with one of the far eastern market places to get them with a smaller shank. Though ground inserts in a 2mm width may be OK on a Myford.

What sort of diameters do you see youself parting off? The MGMN are limited on diameter and also a bit weaker, the blade type I posted will go deeper so larger diameters can be parted. Or if you are only doing small work then there are 1mm inserts and holders, I use thes e alot not just for parting but things like piston ring grooves and the undercut at the end of a thread.

[patgasParticipant @patgas]

Would that parting tool be ok ?
Im only making spacers,washers general bits for restoring motorbikes etc nothing big or of any length

[JasonBModerator @jasonb]

As a tool it is fine, I have the 12×12 (cut down to 12×10), My lathe is a bit bigger but there are plenty of others who use the 2.2mm wide GTN style inserts on Myfords so should be OK and some non ferrous inserts are always an alternative.

With all of them check 10mm will fit. That is not what fits the toolpost it is what fits at ctr height as some toolposts won’t go down low enough to allow 10mm tooling to fit.

[old martParticipant @oldmart]

Using 99% indexable lathe tools at the museum, common to both lathes, we find that the DCGT AND DCMT shape is a favourite, we use 07 and 11 sizes, the 07 being a suitable size for a Myford. Also having accrued dozens of indexable tooling from all the big names plus cheaper Chinese ones and having to reduce the heights from 20mm to 15.53mm, the variations in the steel hardness is minimal. CCMT AND CCGT 06 insert shape is also a good choice for a Myford, and boring bars can be found up to 16mm which share the same two styles of insert ( DC…. and CC….)which is useful.

Boring bars of any diameter have their tip height in the central region which means that if your toolpost can hold them, a bigger bar can fit in a similar height as your ordinary turning tools. For a Myford, I recommend boring bars of 8, 10, 12 and possibly 16mm diameters.

[VicParticipant @vic]

One of the things I noticed some years ago is that many carbide inserts can be bought for a similar price. Provided it suits the type of turning you do, inserts like the TNMG provide six cuttings tips rather than the two or three of some others. The last lot of polished TNMG’s I bought on Amazon for not much money have performed very well on aluminium.
I have an 8 1/2” x 14” lathe which only takes tooling up to a maximum of 14mm. The smallest TNMG tool holder I could find was 16mm so I trimmed 2mm off the bottom. They are made from hard steel but a carbide end mill does the job without any bother.
The tool holder was just under £15 on eBay (from China) and a box of ten inserts was as the time about £12 from Amazon. I have also bought TNMG’s from JB tools for not much money.

 

[old martParticipant @oldmart]

Positive inserts will be better suited to small lathes like Myfords, the neutral ones like TNMG 12  and WNMG 08 thrive on deep cuts in steel, although the aluminium grades work well for steel as well as non ferrous. WNMG 06 are smaller, but probably too big for under 12mm size holders. If you crash with a neutral insert,the opposite side will likely be scrapped also.

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