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new DCMT toolholders

PeterT

Ultra Member
Premium Member
#1
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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PeterT

Ultra Member
Premium Member
#3
If you mean these particular tool holders, the inserts are identical. Just different orientations.
But yes different sizes of diamond inserts exist.
 

Colten Edwards

Member
Premium Member
#4
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
 

PeterT

Ultra Member
Premium Member
#5
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.
 

PeterT

Ultra Member
Premium Member
#8
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/
 

PeterT

Ultra Member
Premium Member
#10
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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Dabbler

Well-Known Member
#12
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.
 

Janger

(John)
Administrator
Premium Member
#13
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. IMG_1387.JPG . 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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PeterT

Ultra Member
Premium Member
#16
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
 

Janger

(John)
Administrator
Premium Member
#18
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
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.
 

Everett

Active Member
#19
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?