Ampco 21 and its characteristic

[AllenT]

Hello everyone!

It's weekend now, I know! But I have to work tomorrow, could anybody in here tell me the characteristic of Material Ampco 21 for CNC Milling, there will be deep drilling, tapping, a lot of roughing, what kind of cutter should I use? EM? Flycut? I use Sandvick flycut for all the tool steel grade 1030, run with air. With Ampco 21, should I use coolant?...

Thanks in advanced for yours help

Allen

[Ron Branch @ Verisurf]

Cut it like SS and use netural or negative to rought it. I have put a slight backwards grind on my drill and they seem to drill great. A dull drill seems to cut better than a sharp drill in this stuff. Finishes nice with regular carbide but worry about holes shrinking when reaming. I use to get .001 oversize reamers when reaming this stuff, but it has been a few years since I messed around with it.

 

HTH

[ablucra]

What Ron said. I use coolants depending on the application of part. We sometimes use it in elevated temp and try to match the conditions of use. As to fly cutting watch for chipping of edges.

 

www.ampcometal.com/.../ampco_machining_recommendations.pdf

[AllenT]

Thank you all very much, I'll try it on monday, lucky me, I still have 1 negative flycut in the shop, it's been sitting there for the last 5 years, never had a chance to use it.

once again, thank you very much for your helps, Mr Ron and Mr Ablucra

Allen

[Kevangel]

More brittle than ampco 18 and if you use a H.S. cobalt endmill it needs to be absolutely brand new..even if it still feels sharp it will cut terribal. I use to make lifters for injection molds outta this stuff..

[jeff]

I've only cut ampco 18 so if it's anything like that, then pretty much what Ron said.

Although I've never ground my drills like that,I just use carbide drill when I can, and yes, expect the reamers to cut small.

I've also found that it cuts better without coolant (for endmills)as long as you keep the heat in the chip.

For materials like brass,copper,bronze, we use a soy based tapping fluid that is hands down the best for these materials.

HTH

[bob flat]

a reamer will take it all off one side, will not follow a hole like in steel. if the holes have to be good mill them close to size before reaming.

[AllenT]

It's very brittle, I'll try to have all holes prereamed by undersizes carbide EM, how about tapping?

once again, thank you all for your helps

Allen