# new DCMT toolholders



## PeterT (Jun 2, 2018)

Found these on AliExpress. I use this particular insert in other conventional tool holders but haven't seen these particular insert orientation. I know it will come in handy. For 10-12$ free shipping its pretty hard to go wrong & quality is quite decent. It might be sold by other Ali vendors, but this is the one I bought from.


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## Colten Edwards (Jul 26, 2018)

just have to make sure you purchase the correct inserts to fit. there are 3 differant sizes of DCMT inserts from what I can tell.


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## PeterT (Jul 26, 2018)

If you mean these particular tool holders, the inserts are identical. Just different orientations.
But yes different sizes of diamond inserts exist.


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## Colten Edwards (Jul 27, 2018)

how I know about the differant sizes of inserts, I have a set that is much too large for the holders I have. I'd have to go check numbers, but pretty well double in size. On a pleasant note, they came within two weeks. Now if I could just get the rest of my crap from aliexpress as quickly, I'd be happy


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## PeterT (Jul 27, 2018)

There are some online resources like this that help decipher the insert size as well as other important featurest; angles, chip breaker styles, coating. nose radii.. etc.
http://www.carbidedepot.com/formulas-insert-d.htm#shape

Many hardcopy tooling catalogs have similar reference matrix breakdowns. It can get a bit confusing because some manufacturers have variants of these designations, so sometimes you have to go on their websites & look for 'cross reference'. Then to complicate matters, particularly buying offshore, is there are other standards that may be 100% equivalent to these but use a different ISO? numbering system. And they may offer inserts which are not as popular in N-Am, but not necessarily a bad thing if the tool holders are reasonable. 

If you need specific help, let us know, maybe we can help. Generally (for my hobby purposes) I have found its well worth the effort to buy offshore because they can be very expensive domestically.


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## buckbrush (Sep 30, 2018)

Bangood has a lot of carbide inserts and holders for cheap, as well as Ebay.  You want positive rake inserts for hobby type machines.


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## buckbrush (Dec 14, 2018)

dcmt is positive rake. Your holders will also take dcgt inserts which are ground razor sharp.


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## PeterT (Dec 14, 2018)

buckbrush said:


> dcmt is positive rake. Your holders will also take dcgt inserts which are ground razor sharp.



I don't think that's necessarily true. I see positive, neutral & negative DCMT. One rake might be more prevalent than the other... Interestingly I don't see rake in the designation, but catalogs & vendors have weird coding & specifications sometimes.
http://www.carbidedepot.com/formulas-insert-d.htm#shape

different rakes
https://www.amazon.com/Kyocera-Uncoated-Positive-Continuous-Finishing-Medium/dp/B07B4JWKHS
https://www.zoro.com/sandvik-coromant-turning-insert-dcmt-3252-um-1125-dcmt-3252-um-1125/i/G7073437/
https://www.kodiakcuttingtools.com/...nd-negative-rake-carbide-inserts-for-turning/


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## buckbrush (Dec 15, 2018)

the c in dcmt denotes a positive rake, 7 degree's.

http://www.carbidedepot.com/formulas-insert-d.htm


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## PeterT (Dec 15, 2018)

See this is where I get confused. The 2nd digit in that link shows a diagram of what they call 'clearance or relief angle' & corresponds to what  is usually called 'end relief' in typical HSS cutter terminology. We are after corresponding 'rake angle' which is the top side geometry & what the material sees. That's where I assumed the positive, neutral, negative comes from. But I think that is defined by the pocket plane - a neutral pocket plus a neutral insert = neutral or 90-deg to work. A positive pocket + neutral insert = positive rake. My pockets look to be in same plane as shanks. Now whether there is something funky going on right at the very edge of insert I cant say. Will have to delve into this further. Int milling cutters its very common to see exaggerated angled pockets.


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## buckbrush (Dec 15, 2018)

now you have me confused!


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## Dabbler (Dec 15, 2018)

So Peter for a given insert, it can either be a positive rake or neutral.  Negative rake tools usually have  N for clearance angle,  but I have even seen a few positive rake tools that have no clearance angle.

Just check the actual insert before buying quantity, and you will be fine.


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## Janger (Dec 25, 2018)

Merry Christmas Everyone. I was chatting with Dabbler and he suggested posting on the turning tools I was showing him. In the picture you can see the chuck backing plate spacer I am in the middle of making. It's a 4140 4" diameter ring. I turned the part on the lathe with DCMT tools. The ones in the picture. Finishing cut details: Speed was as fast as I could make the lathe go, 2000rpm, with a DOC of about 0.5mm (0.020"), power feed as slow as the lathe would go 0.0009" per rev. The higher turning speed helped a lot. 1400 RPM was also pretty good but better at 2000 RPM.

The tools are from China nicecutt.com and they sell on aliexpress and direct. The tools were about $10USD each and the inserts are $2.5USD also from them. Plus shipping. The tools are 16mm or 5/8" thick and use DCMT0702 and DCMT11xx something inserts. Model SDJCR1616H07. 


. I used the smaller one for the finish pass and was roughing with larger tool. They performed similarly. They have an extensive catalog. I've also bought indexable end mills and face mills from them. They are good too and inexpensive.


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## YYCHM (Dec 25, 2018)

What machine are you doing this milling on?


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## Janger (Dec 25, 2018)

Lots on my mill in this thread. I bought it from Alex. I think it's pretty big, Alex think's it's a mini.  It's a First brand (House of tools) horizontal vertical mill converted to CNC. 
https://canadianhobbymetalworkers.com/threads/converting-mini-mill-to-cnc.204/


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## PeterT (Dec 25, 2018)

Really nice finish on the 4140, congrats. 

Just because I've had threading on the brain lately, I see the same company sells insert threading shanks. 
http://www.nicecutt.com/Product.asp?Catalog=65&Child=0

Guess this is their AliExpress store front. 
https://www.aliexpress.com/store/1981621?spm=2114.10010108.100005.1.6807803f8kDgZt

The tooling looks a smidge more expensive than some generic black, but I didn't check rigorously. Do you find the quality better?
The silvery color (hard chrome) finish looks suspiciously similar to M100DEX brand... but for significantly less $
https://www.traverscanada.com/4-piece-turning-boring-sets/p/38804/?lite=true&pricelistname=CANSITE


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## buckbrush (Dec 25, 2018)

I have found Bangood and some china based sellers on Ebay much less expensive. just saying.


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## Janger (Dec 25, 2018)

PeterT said:


> Really nice finish on the 4140, congrats.
> 
> Just because I've had threading on the brain lately, I see the same company sells insert threading shanks.
> http://www.nicecutt.com/Product.asp?Catalog=65&Child=0
> ...


Yeah that M100DEX looks similar doesn’t it. And for lots more money. I do think this stuff is pretty good quality Somewhat better than the usual black oxide tools. I couldn’t quantify it but the results speak for themselves. I like sandvik but that’s not for me too pricey. I’ve used the regular Chinese inserts and these ones from nicecutt they seem better to me.


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## Everett (Dec 25, 2018)

That is a very nice surface finish.  As for insert tooling, all my carbide insert stuff came from eBay vendors out of China.  Had to wait a while for each of them but the price made the wait worth it.  I could see a production CNC place wanting consistency between holders and bits to be tight when trying to keep a production machine running with fresh bits all the time, but for those of us at home with mostly manual equipment the cost difference isn't worth the name brand when we have other needed tooling that could use that budget space.  I've never ordered from Aliexpress or Banggood, has everyone here who has ordered from them had mostly decent experiences with them?


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## buckbrush (Dec 26, 2018)

I have had good experiences with them, check out "Pierre's garage " on YouTube, he is a canuck and test's some of their stuff.


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## Dabbler (Dec 27, 2018)

I've had very good experience with Banggood.com, but none with aliexpress.


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## Everett (Dec 27, 2018)

Thanks, was just curious what they were like for the regular consumer.  Rob (xynudu) from Australia, Pierre, and John Mills in England have all done reviews for Banggood so they're likely to be treated well, but was interested to see what they were like for regular sales.  I've only used eBay and some Amazon but the vendors have to behave themselves in those environments to a certain extent or lose their credibility (and therefore sales).


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## PeterT (Dec 27, 2018)

I've used AliExpress & Ebay predominantly. No problems with Ali other than shipping time which is a common issue regardless if originating from Asia. I have not used Bangood but for no particular reason. Sometimes I see the exact same item and/or even same seller across all 3 platforms.

Maybe its me or the particular machining type stuff I'm looking at, but seems like Ali has increasingly more items identified for shipping by DHL or similar faster courier mode vs. the classic TheSlowBoat free shipping or minimal shipping cost mode. That expedited / trackable? mode cost can add substantially. Maybe its a trend or maybe just select sellers but I have noticed expedited is the ONLY way they ship, no SlowBoat is even available. Maybe they are bigger more industrial sellers or maybe they have had too many delivery issues? The expedited seems a bit cheaper than ordering the same item out of USA weight/size factored by USPS, but this is just a generalization.

Another interesting thing is going to be how tariffs will/will not apply to us 2019+. If a USA company imports a tariff add Chinese item, I suspect that will be a cost add to them & this dinger will get passed onto a CDN order. That's before any new-Nafta, GST etc. Now if you bought the exact same item from China direct, we don't have these trade war tariffs (yet) so maybe mitigating these dispute tariffs?  Its a mess, that's all I know.


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## Johnwa (Dec 27, 2018)

Most of the free shipping has disappeared from Aliexpress.  
 Depending on the vendor shipping starts at about $6.  Those that only use couriers are much higher.


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## Janger (Dec 27, 2018)

Johnwa said:


> Most of the free shipping has disappeared from Aliexpress.
> Depending on the vendor shipping starts at about $6.  Those that only use couriers are much higher.


I was reading about this today. Apparently the postal strike caused the vendors to stop post shipments as they were being refused by Canada post. I hope this gets resolved but we’re small potatoes...ugh.


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## Downwindtracker2 (Dec 29, 2018)

We assume postal service is efficient and honest, if somewhat slow. In a lot of the world that simply isn't true. I've gotten books from South Africa,, they use courier if they want to be assured it will arrive.


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