Black oxide coating

[dredd]

Normally, I order Bright drill bits. Doing alot of drilling in aluminum, I see that MSC and Enco both do not recommend black oxide coated drill for use in non-ferrous materials. Why? Can anything bad happen if I drill aluminum with black oxide?
Thank you
Chuck

 

[jgedde]

When they say non-ferrous, they mean aluminum. Generally black oxide bits gum up faster than TiNi coated or bright bits. The built up edge resulting from gumming gives a less than optimum surface finish.

John

 

[Rbeckett]

Alli gets stuck on the flutes and scratches up the inside of your hole. Then you gotta ream it or use some paper to clean it up. I use the Yellow TiNi thunder bits from Snap-on, and keep them super sharp with my drill doctor 750X. Took a bit to really master the technique, but now I can touch up a bit perfectly in no time at all. Just remember on gummy or soft material, turn the bit as slow as possible while still pulling a regular chip. Hope that helps improve your holes........ Heh heh heh

Bob

 

[refinery Mike]

I have read that you are not supposed to use the titanium nitride bits (Gold colored) on aluminum either. Just the plain shiny silver colored ones. Supposedly the aluminum sticks to the coating as well. I have never had a problem with them, But if i want a smooth hole i generally bore it out. Anyone else got the straight skivvy on this.