12x36 Lathe: CCMT21.51 or 32.51?

[Splat]

Mikey, good advice. I'm gonna go with the 1/2 shanked SCLCR and SCLCL bars that hold CCxT32.51 inserts.

I've been reading a lot on CCMT or CCGT inserts. Well, actually I've been reading about all different inserts. My brain is overloaded. First job will be on hardened steel. I don't know what its made out of but definitely can't draw a file across it. After that it'll mainly be for steel, few stainless jobs, and some aluminum. Thank you.

 

[darkzero]

Yeah, I edited out the Grizzly set outta my post after your reply cuz I figured exactly what you said. I really only need the turning tools, and not even really the left one either for now. To heck with it. Gonna go to McMaster tomorrow and pick up a 1/2"shank SCLCR and SCLCL holders. Cstmr service just told me they're Dorian brand. At least I can get the needed work done tomorrow. Get one thing done and it all sets up for the next job, doesn't it?

Oh, that's good to know. Many of my indexable tool holders are Dorian. Not that I prefer Dorian over other name brands for any particular reason, I got them from my local Travers. But I do prefer to get a name brand over generic imports.

 

[Splat]

Yes, I'd rather go name brand. Dorian apparently is made in Australia...at least the SCLC tools from what I gather. Well, I have tangential tool holders with 1/2" shanks. I use 1/4" HSS bits in them. They work great on my machine and I can get in pretty close with them. So which shank size for the SCLC tools would you recommend, 1/2" or 5/8" shank....am I nitpicking here? Thanks.

 

[darkzero]

Yes, I'd rather go name brand. Dorian apparently is made in Australia...at least the SCLC tools from what I gather. Well, I have tangential tool holders with 1/2" shanks. I use 1/4" HSS bits in them. They work great on my machine and I can get in pretty close with them. So which shank size for the SCLC tools would you recommend, 1/2" or 5/8" shank....am I nitpicking here? :***** slap: Thanks.

Australia, WTH? Where did you see this info? All my Dorian stuff in made in the USA, including my insert holders, they say Made in the USA right on them.

 

[darkzero]

Yes, I'd rather go name brand. Dorian apparently is made in Australia...at least the SCLC tools from what I gather. Well, I have tangential tool holders with 1/2" shanks. I use 1/4" HSS bits in them. They work great on my machine and I can get in pretty close with them. So which shank size for the SCLC tools would you recommend, 1/2" or 5/8" shank....am I nitpicking here? Thanks.

Most of my holders are 5/8" mostly cause there are a lot more tools available in 5/8 shank than 1/2. Nothing wrong with 1/2 though, some of my tools are 1/2. You'll probably not be able to notice much of difference unless you hang the tool really far out and/or take deep cuts.

 

[Splat]

I was searching Dorian tools around the web and some sites said Australia. Others did say USA. Be interesting to hear from Dorian if particular tools are made elsewhere.

 

[darkzero]

I see. I've only known Dorian to be made in the USA. Of course things change. And Australia is so odd, they are not known to make machining related tools.

 

[Splat]

Yeah, I'm not saying they're right. Hopefully, they're wrong and they are 100% USA. Will, what inserts (Iscar, Hertel, etc.) are you using on your main turning bars if ya don't mind?

 

[mksj]

I would go with 5/8" holders if you have a BXA sized tool post, these typically take the 32 size inserts which will be more robust for just about everything, the smaller inserts 1/4" are more useful for small boring, facing, etc. The hardware, insert screw and anvil (on some holders) is larger and are more durable with the larger inserts. Anvils or replaceable seats and thread inserts usually start 5/8" holders and larger.

I haven't turned hardened steels that are file resistant, I do not think you will have very good results with regular coated carbide, but you can check the insert coating as to the hardness rating/material it is rated for. There are coated carbide, cermet (ceramic), cubic boron nitride (CBN), polycrystalline diamond (PCD) inserts and PCBN (Polycrystalline Cubic Boron Nitride) which is rated for turning hardened steels (45 to 70 HRC). What you use depends on the hardness. You may be able to get by with a cermet, they are very fragile and are primarily for hardened material. All these operate within a narrow operating parameter range, and can easily be damaged.

 

[macardoso]

I've done a little bit of hard turning on hardened steels 50-60HRC using plain carbide. I've found that the cutting forces are tough on your machine so I opted for shallow depths of cut using a CCMT with a very small nose radius. This was a manual lathe. The more exotic insert materials are much better suited for the job, but don't be afraid to try out a plain (coated) carbide insert or two.