Can anyone identify these inserts

I was given a box of various tool inserts that came from a closed down engineering company. There were some of these. They appear to be double sided. Giving 6 cutting surfaces, but no angle on the cutter. Do these fit some sort of holder that is at an angle to get the correct cut.

Steve.

you are correct, they are also intended to have an insert shaped blank beneath them and fit tool holders around 25mm square +

Big stuff

Probably TNMG

The lack of side relief "N" and what looks like quite a large tip radius would mean they are not ideal for your Myford so save your money getting a holder. They are better suited to heavy machines capable of heavy cuts.

Yes I guessed they were probably from something big. They are twice the size of the ones I have for my machine. I was just curious as I have never seen any like them. But as said they did come from an engineering company. I guess they had lathes a tad larger than my Myford. .

Steve.

Edited By Steviegtr on 12/03/2020 19:28:27

I use TNMG frequently, the 16mm size which is too big for a Myford unfortunately, and have never seen smaller ones. I have about 6 different grades for steel, cast iron and stainless, as well as the aluminium grade which is good for finishing cuts on all types of ferrous except the harder steels. You get six edges per insert unless loosing an end ruins the other side at the same time. If yours are too big to use on your lathe, then they make great scrapers screwed on to a handle, and the edges can be sharpened by rubbing on a coarse diamond lap.                                    Because they do not have any relief, they are held in the tool at a 7 degree downward angle on an axis through the tip and the centre hole.

Edited By old mart on 12/03/2020 19:32:44

Don't know how the Myford compares to a WM280, I use the 16mm tnmg inserts on the WM280 and I find them to perform very well. The only limitation I find with them is when turning to a small diameter as they tend to push on the work piece.

I have the same insert mounted on a flycutter and works fine as well.

I have just measured my holders & they are a tad under 15mm So without mods the 16mm will not fit. Shame as I have a stack of them. A flycutter maybe. I have just bought a milling machine ,so I will be looking out for a flycutter that takes those inserts. Any idea of the make.

Steve.

I use that type of 16mm insert on my Southbend lathe which is a similar size to a Myford and the cutter is my first choice for machining. They are very robust and can leave a good finish and last forever (almost). The 6 cutting edges are a bonus, making them very economical.

I did however, have to machine a bit off the bottom of the tool holder as they were sitting too high.

Paul

You must have read my mind as that is what I was thinking of doing as a possible way of using a 16mm holder. I now have a milling machine so the possibilities of doing this sort of thing have opened up for me. Also I am going to have a go at making some toolholders from scratch using the mill. I need to buy some dovetail cutters 1st. Plus some suitable steel stock. Not sure what steel would be best for toolholders. Maybe just Mild steel. Thanks for the info. Regards.

Steve.

These toolholders were not expensive and bought on ebay. The holder was not hardened and machined as though it was MS. They have a wedge type clamp and a decent size screw for holding the insert, much more rigid than a screw thru the insert. They stand up to a lot of abuse and I have not had an insert break. (turning irregular shapes, rough cast iron, etc).

**LINK**

Paul

The make is DIY, the one I have is a "bit" oversize for my machine, but it's adjustable so I can control vibration.

You can use the mill to take off the required amount off the bottom of the lathe tools. HSS cutters may not fare well on the steel of the tool shank. I buy 20mm tooling and reduce the height to 17.52mm using a shell mill with carbide inserts intended for steel. The inserts do not last long doing this.

I have plenty of round stock. Guess now with the milling machine it is time to buy some good quality square stock. All I have is 5 or 6 HSS slot mills that I got given by a friend. They say buy any machine & then spend a fortune on tooling.

Steve.

Hi Stevegtr

Some of the cutting tip suppliers at model eng shows are and may be inclined to trade you those for some of a more appropriate size (believe me what ain't good for you is great for a another) cleaned up a bit with WD and a cloth good as new will swap for new.

£5.00 useless to you tip swapped for a £3.50 useful to you tip. supplier makes £1.00 -£1.50, you get tips to fit without the cost of make or buy a holder. Win Win

Sounds good. Thanks

steve.