SCBCR and SCKCR tool holders that make use of "unused edges"

[andrewgr]

I get the theory behind a toolholder that gets some mileage out of the traditionally unused edges of the CCMT/CCGT carbide inserts.

In practice, I'm not sure what they should/could be used for-- I mean, the "unused edges" are unused for a reason. The catalogs say they're for facing and turning, which isn't super useful.

Does anyone use these semi-regularly? If so, what do you use them for? Are there particular angles, or materials, where they're called for? Or if not, where it doesn't matter very much (roughing passes?) so you might as well use them rather than the "good" edges?

 

[Cadillac]

Facing and and breaking the edge on id and od of cuts. Why not is the question you have two other good sharp edges?

 

[MrWhoopee]

where it doesn't matter very much (roughing passes?) so you might as well use them rather than the "good" edges?

Use 'em anywhere their shape will allow, they're "free" edges. Interrupted cuts, torch cut edges, cast iron with hard spots, that sort of thing.

I bought two holders for SCMT inserts, cut them short and welded them butt-to-butt. They live in an AXA holder and have become my go-to for facing, turning (with no shoulder) and chamfering. The SCMT has four "good" corners instead of two and gives a 45° chamfer. I save the "good" corners of the CCMT inserts for when I actually need them.

 

[darkzero]

I don't use those tools holders on the lathe but I do use a facemill in the mill that uses the "unused" corners for CCMT/CCGT inserts. I use it quite often, much more than my 2.5" 45° FM. I really love this thing.

Dorian Recycle Cutter - Face Mill

Back when I was in the market for a face mill I came across an article about Dorian's recycle cutters. Been meaning to get one & when I finally remembered to order one yrs later, Dorian was out of stock which lead to the few vendors that carried them to be out of stock also, well at least for...

www.hobby-machinist.com

 

[paradox_pete]

The way I see it, the obtuse angles can be used for any turning or facing operation that doesn't involve a shoulder. I actually use them for most of those operations and save the acute angles for situations where I AM turning or facing to a shoulder....

 

[Mitch Alsup]

I have both 80º and 100º CNMG tool holders--allowing me to get all 8 corners out of a single CNMG insert.

When I need something really sharp, I put a CCGT insert in the CNMG holder.