What's new
What's new

We are turning a single part and don't really want to order inserts, we have inserts for steel, stainless steel and cast iron. Any suggestions

Tamster

Plastic
Joined
Apr 21, 2022
We are drilling & turning a single part that is 5" brass bar stock x 10" long, I don't really want to order new inserts for just these 2 parts. We have inserts for steel, stainless steel and cast iron. The anti vib bar they want to use is a TNMG insert. If we use the inserts with a steel grade any suggestions on speed and feeds as well as nose rad to use.
 
Last edited:

TeachMePlease

Diamond
Joined
Feb 11, 2014
Location
FL
Use the smallest nose radius you've got, go real fast.
It's brass, not inconel. (Assuming this isn't some exotic brass alloy I've never heard of)
 

michiganbuck

Diamond
Joined
Jun 28, 2012
Location
Mt Clemens, Michigan 48035
When in doubt go to the old school and find the closest of what you have.

if you have a diamond wheel you might match the given, by hand would be OK, 220 grit would be OK.
If the CI insert is fingernail sharp that might do OK.
If not I would go with/try the steel insert.
 
Last edited:

implmex

Titanium
Joined
Jun 23, 2002
Location
Vancouver BC Canada
Hi Tamster:
The reason to optimize the choice of tooling is to do one or both of two things:
1) Make a production process as efficient as possible.
2) Successfully cut a difficult material.

Neither criterion applies to your problem...you don't need to squeeze the last drop of efficiency out of your process and brass is pretty easy to machine unless it's some weird grade like Naval Brass.
So grab just about anything and give it a go.
Pick your normal grade of whatever you use to cut whatever you cut most of, use the feeds and speeds you normally would and try it out.
Chances are it'll be perfectly adequate and you'll get your parts done before you even have time to fuck around with it.
Don't overthink it...just DO it...it'll be fine.
If it's not fine in the roughing, you can use your common sense to play with it until it IS fine.

Cheers

Marcus
www.implant-mechanix.com
www.vancouverwireedm.com
 

Nmbmxer

Hot Rolled
Joined
Jun 22, 2008
Location
VA
I would use the most positive insert you have then take a diamond hone and knock the back and side rake angle down close to 0°. I've also machined plenty of brass one-offs using the general turning inserts and not had issues, more problems drilling and having the bit get sucked in. Dubbing the rake back on drills is easy as well.
 

rons

Diamond
Joined
Mar 5, 2009
Location
California, USA
I just finished grinding a 30 degree bevel on a brazed carbide bit. I have to put a 30 degree step on the inside of a cylinder. The step is from one inside-diameter
a smaller inside-diameter. The distance from step to step is like .055. I thought about getting some inserts that can get into tight inside corners and cut correct
angles but I'm just doing this part once (I hope). Any recomendations?
This tool bit has been ground down over time so that the carbide piece is less than 1/2 the original size.

The Chinese brazed carbide bits would probably be alright. They have been making them long enough. In the past I've seen that the carbide edges line up
with the tool shank. But a diamond stone can make any of those bits be anything you want. And keep the expensive inserts for nice finish work.
 

DDoug

Diamond
Joined
Oct 18, 2005
Location
NW Pa
Exactly, I don't understand the fuss. Two parts out of brass, you could sharpen a HSS blank on a belt sander and use it.
Because the OP forgot the material, then went back and edited in "Brass" when I asked "what material", see my quote of their original post, there is no mention of material.
 








 
Top