turning or boring 440c or CPMS90V Stainless Steel

No direct experience but CPMS90V has boatload of carbon and vanadium =carbides and it is going to be rather nasty at 58HRC compared to something like plain high carbon steel.
CBN would hold up best but if this is just one piece I'm not sure it is worth the cost and experimentation.
Seco TH1000 carbide grade has been also mentioned here about hundred times.

I've probably mentioned Seco TH1000 98 of those 100 times. The others who mentioned it, probably heard it from me.

It does work well - very well - in hardened steels.

If production, I'd look at CBN. for 1 or 2, TH1000 will do just fine.




Those high-vanadium powdered metals will be abrasive. Vanadium-carbides are extremely hard, however the PM materials will make it a little easier to cut than say, D2, because the grain-size should be much smaller, with much better carbide distribution. You should getter better, more uniformed wear cutting PM material.

If you're sticking with carbides, consider cermet grades as well. These will actually give you a harder substrate than even carbide. Seco's TP1030 cermet grade will have the same coating as TH1000, so that should be an option. Kyocera's PV720/710 grades, or other "mega-coat" grades would be a good option for cermet grades as well.

Ceramics will work as well. However, you may get a finer cutting edge with a lightly-prepped' CBN insert, or TH1000 with the correct chip-breaker. Especially important for boring operations.

Seco TH1000 is a dream for IHCP and hardened carbon steels.

I've tried to turn D2@63RC with Seco TH1000 CNMG432 M5 with 0 luck.
The edge crumbled before it cut more than .020".

Jashley might know how CPM @ 58 compares to D2 @63, but I'd look to CBN.

What happened to this thread?

I was replying to another post, now the thread shows my reply as the first post and I show up as a thread starter?
Database crumbling to pieces again?

MattiJ said:

What happened to this thread?

I was replying to another post, now the thread shows my reply as the first post and I show up as a thread starter?
Database crumbling to pieces again?

Click to expand...

Yeah, that's odd. Google turns up this when searching the thread title:

"Nov 8, 2020 — Anyone ever turn and bore 440C and or CPMS90V Stainless steel in the 58HRC range? I have a RFQ for a ring about 1/4" thick about 1/4" wall ..."

So it would be too late for the OP to delete that post. Were there any others before your (now first) post missing?

Milland said:

Yeah, that's odd. Google turns up this when searching the thread title:

"Nov 8, 2020 — Anyone ever turn and bore 440C and or CPMS90V Stainless steel in the 58HRC range? I have a RFQ for a ring about 1/4" thick about 1/4" wall ..."

So it would be too late for the OP to delete that post. Were there any others before your (now first) post missing?

Click to expand...

IIRC my reply was the first one.

If I recall correctly OP was newbie with only few posts. Maybe turned out to spammer and got his account deleted? BUT the thread turned out weird anyhow..

IDK what happened either.

As I recall, I questioned the thread title in this section, but it seems like when I read the first post - it didn't seem quite so "wrong board" at the time.

If the opening post had gotten deleted, the whole thread should have gotten tanked.
???

As it sets now - I think that I am going to move it to the CNC board.


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Think Snow Eh!
Ox

ManualEd said:

Seco TH1000 is a dream for IHCP and hardened carbon steels.

I've tried to turn D2@63RC with Seco TH1000 CNMG432 M5 with 0 luck.
The edge crumbled before it cut more than .020".

Jashley might know how CPM @ 58 compares to D2 @63, but I'd look to CBN.

Click to expand...

I would try MF5 chip-breaker. It's a sharper edge prep, and should cut with less tool pressure.

M5 has a negative land at the cutting edge. It's probably my favorite of Seco's chip breakers for steel/cast/400-stainless materials. Not my first choice in hardened steels, though it must work pretty good or they wouldn't offer it. (TH grades contract at different rates during sintering, and thus require their own press-tooling for manufacturing.)

I think I've said it before, but the carbides within D2 are YUGGGEEEE compared to other steels. Thus, why it's so tough to cut & grind when hardened. (I've worked lots of it in the past.) It is exceptionally tough too. I'm not surprised to hear that it crumbled the edge quickly.

I'd predict that MF5 would give better results.

cBn would be better though, if the job had any quantity at all.