View Full Version : Regular Vs. Aluminum Insert Centre Height

04-24-2018, 12:06 PM
I'm wondering if someone has experience with the typical carbide inserts versus the polished ones for aluminum/nonferrous, they often look to have aggressive 45 degree rakes built in and seem like they would have a different centre height? I am considering getting some in CCMT09 and APMT for my face mill, to see how the finish is in aluminum, but it would be really nice for the lathe tooling if I could just unscrew the regular insert and put in the aluminum one without having to change the QCTP height screw accordingly.

I suppose I could shim the normal insert and then remove the shim when switching to the aluminum insert, whcih would be easier to do once than futz with the QCTP adjustment each time I swap.

Does anyone know if this is an issue ie. do the inserts just look that way or do they need different heights?

Also I'd love to hear of any adventures in polished inserts, are they worth the trouble for people who work in steel and aluminum with equal regularity. I'm curious if they'll get a closer to mirror finish when facemilling aluminum instead of the smooth but visibly scratchy surface I get with the normal inserts. What I've seen with the polished SEHT insert on a Tormach Superfly seems very good.

04-24-2018, 12:15 PM
They are the same...

They are also pretty darn handy for things that aren't aluminum... Think of them as a nice sharp piece of HSS, that can be run 3 times as fast..

I use them ALL the time on small stuff when you can't get the surface speed to let a honed insert work its magic. Especially on mild
steels and annealed 4xxx alloy steels, they work great for getting a good finish when you can't get the speed.. They work pretty
good in stainless and Ti also, as long as you don't beat on them too hard.

old mart
04-24-2018, 12:53 PM
I use several types and they seem to be the same height. Many of mine are super cheap from China and they work very well on medium to mild steel. They are so cheap, 1 each or less that there are no worries about trying them on anything within reason. Stock up with lots with different nose rads and treat them like hss.

04-24-2018, 02:48 PM
I ordered some, should be great! Thanks guys.

04-24-2018, 03:35 PM
Inserts come in different thicknesses, regardless of their best use.