Mysterious inserts

[Michael GilliganParticipant @michaelgilligan61133]

I have just been looking for some narrow ‘Aluminium-cutting’ inserts to abuse … and came-across this listing on ebay:

https://www.ebay.co.uk/itm/155695820702

Before commenting … Please look at all the photos in the listing.

Could someone kindly explain … have these been re-worked ?

MichaelG.

[bernard towersParticipant @bernardtowers37738]

Looks very much like it Michael mine look like the rest of the photos. But could be an interesting rework.

[Michael GilliganParticipant @michaelgilligan61133]

I have just asked the seller … so we may know sometime soon

MichaelG.

[JasonBModerator @jasonb]

The main photo look more like some MGGH ones that I have where there is just a flat top to the cutting edge but the other photos have the moulded tops to curl the swarf so hard to say which you will get.

Two types shown with a good explaination of why they suit the smaller machines here

Said inserts in action

[JasonBModerator @jasonb]

Here you go sharp MGGN inserts but intended for stainless and other Ferrous alloys so they are not polished like the ones for aluminium as sticking is not an issue with the ferrous metals but do have the typically ground cutting edge to reach the “**G*” tolerance code.

[Michael Gilligan]

On 4 September 2025 at 21:57 Michael Gilligan Said:

I have just been looking for some narrow ‘Aluminium-cutting’ inserts to abuse … and came-across this listing on ebay:

https://www.ebay.co.uk/itm/155695820702

Before commenting … Please look at all the photos in the listing.

Could someone kindly explain … have these been re-worked ?

MichaelG.

I love adverts like these, starts with Aluminium in the title, then you get ambiguous photos followed by a write up that says primarily for cast iron. Recycling at it’s best.

[JasonB]

On JasonB Said:

Here you go sharp MGGN inserts but intended for stainless and other Ferrous alloys so they are not polished like the ones for aluminium as sticking is not an issue with the ferrous metals but do have the typically ground cutting edge to reach the “**G*” tolerance code.

Many thanks, Jason … you’re a star !

The seller responded very quickly and politely … but confusion remained.

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

For info.

.

Hello, I’ve found two additional links for you. Could you please check if these are what you need?

Reply

Your previous message

Thank you for the very prompt reply … but NO

It is the modified inserts that I want
… I have added a red arrow to your photo

Is this shape actually available ?
Thanks again.

4-68086:

Hello, I believe the model you’re looking for might be available in this listing: https://http://www.ebay.com/itm/166884467867?var=466557463193<;/a&gt; (eBay item number: 166884467867). Please feel free to check it out, and if it doesn’t meet your needs, don’t hesitate to reach out to me anytime.
Your previous message

I am very interested in these inserts.

Could you please clarify … Have they been re-worked to the unusual shape shown in photo 1/6

Thanks in advance
MichaelG.

[JasonBModerator @jasonb]

That second listing is much like the ones I showed. Check your messages for polished aluminium specific ones (last on the page)

[Michael GilliganParticipant @michaelgilligan61133]

Thanks again, Jason

MichaelG.

[cogdobblerParticipant @cogdobbler]

The seller is obviously a shopkeeper and not a machinist with intimate knowledge of his products. And almost certainly relying on Google Translate for the English text in his listings, which is disastrously hopeless  between English and most Asian languages. The results, in my extensive experience, range from laughable to downright criminal.

[old martParticipant @oldmart]

I have some 1.5mm inserts like that, but can’t remember if they have the standard chip breakers. The photo’s show several variations. They would probably need a 1.5mm blade or tool, not any other size.

[andy198712Participant @andy198712]

You see it a fair bit in Chinese machine parts adds. Varying pictures for the same item.
One example I saw today was insert milling heads, some cast ally others in the pics were billet steel…. For the same item 🙁

[VicParticipant @vic]

I was trying to get a 4” CBN cup wheel a while back, but I gave up as the descriptions always seemed to mention Diamond in the same sentence.

[bernard towersParticipant @bernardtowers37738]

Try Abtec Industries, Wisbech they arte floor to ceiling with that stuff and very helpful.

[DiogenesParticipant @diogenes]

..or ‘Midland Abrasives’..

[Michael GilliganParticipant @michaelgilligan61133]

[ Deleted ]

[SillyOldDufferModerator @sillyoldduffer]

Not reworked I think.  The retailer has simply mixed up photos of different members of the MGMN family.  The family has at least six variants of the same basic shape and dimensions but with different edges and chip-breakers.

I guess ordering a box could result in a mixture arriving too, because the seller isn’t an expert.

A variety box arriving may not be bad unless the purchaser knows exactly which one he needs.   Manufacturers know because they carefully select inserts to get the required finish from a given material at minimum cost.  And they have the fast, powerful, rigid machines needed to run inserts to specification.  As hobbyists rarely have ‘ fast, powerful, rigid machines’, it’s often impossible for us to run inserts to spec.  And unlike industry, we cut different metals with the same cutter, possibly not knowing exactly which alloy it is. We have to experiment for best results instead, and it may be one of the MGMN variants performs better than the others.

An example of fruitful misuse: the sharp inserts designed specifically for cutting Aluminium at super high RPM work very well on steel at ordinary cutting speeds.  But this seems largely unexplored: be good for a team of hobbyists to methodically work through inserts in a home workshop setting and publish the results.  A nice table of what works and what doesn’t.

Dave

 

 

 

[SillyOldDuffer]

On SillyOldDuffer Said:

Not reworked I think.  The retailer has simply mixed up photos of different members of the MGMN family.  […]

 

An example of fruitful misuse: the sharp inserts designed specifically for cutting Aluminium at super high RPM work very well on steel at ordinary cutting speeds.  But this seems largely unexplored: be good for a team of hobbyists to methodically work through inserts in a home workshop setting and publish the results.  A nice table of what works and what doesn’t.

Dave

 

 

 

An excellent proposition, Dave … ‘though I doubt it will ever happen

MichaelG.

.

P.S. ___ For clarity: Thanks to Jason’s sage advice, I have ordered some [sharply ground] inserts from elsewhere, for my own experimentation on a small lathe.

Personal circumstances dictate that this will be a protracted exercise … so please don’t hold your breath !

[noel shelleyParticipant @noelshelley55608]

Diogenes mentioned Midland Abrasives, yes they were helpful but the goods were far from good – in this case a very badly out of balance grinding wheel. Only a great deal of time and effort got it anywhere near right, and the cost of a J&S balancer. Noel.

[bernard towersParticipant @bernardtowers37738]

My sharp ones arrived today so we will have to compare notes Michael.

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