feeds and speeds for brass

[john dakinParticipant @johndakin59277]

[john dakinParticipant @johndakin59277]

i need to drill a number of small holes into cz120 engraving brass, the holes are 1mm and 2mm diameter and the stock thickness is 3mm thick, the holes are all through, the problem is that my drill bits keep breaking, I'm drilling on a cnc mill, can anyone suggests feeds and plunge rate speeds etc, it's been suggested that I use a parabolic drill would this be a good idea, any suggestions welcome

[Thor 🇳🇴Participant @thor]

Hi John,

When drilling brass with such small diameter drills I usually run about as fast as my milling machine will go – around 2500 rpm. When drilling in brass the drill easily grabs the material and a tiny drill then tend to break. There seems to be special drills for brass, have you tried them?

***Link***

I stone the ordinary twist drills I use for brass, like described here.

Thor

[Neil WyattModerator @neilwyatt]

Flutes can clog very fast at the speeds needed for small drills. Have you tried 'peck' drilling.

Nil

[john dakinParticipant @johndakin59277]

What's the name of those special drills for brass called

[Russell EberhardtParticipant @russelleberhardt48058]

Posted by john dakin on 26/10/2016 14:08:58:

What's the name of those special drills for brass called

Slow (or Low) Helix Drills.

Russell.

[Neil WyattModerator @neilwyatt]

Slow spiral drills.

Neil

[Michael GilliganParticipant @michaelgilligan61133]

John,

'Engraving Brass' should drill nicely with zero or negative rake; so any spiral is really a hinderance … The post at the top of this page gives good advice.

http://yarchive.net/metal/brass_drilling.html

MichaelG.

.

Edit: Yes, I know he's talking about big drills; but the principle is sound !!

Edited By Michael Gilligan on 26/10/2016 15:38:15

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