View Full Version : Drill bit for brass

22-09-2016, 10:01 PM

I got a CNC converted RF-45 clone and want to drill 3mm holes (+300) through brass pieces in a 30 fixture. I don't want to pre-drill and was thinking that a solid carbide stub drill is good, as it deflect less and can hold up to the abrasiveness of the brass. Any other recommendation on a good drill for the job? Speed, feeds?




Boyan Silyavski
23-09-2016, 05:39 AM
Hi Brian,

This (http://www.mycncuk.com/threads/10043-How-to-drill-faster-in-brass?highlight=drilling+brass) is my experience. You could read there about what speeds and feeds i used. All was done using high quality 3mm micro grain carbide bit/ not chinese/ . You could buy them from ebay, search for Kyocera. Obviously even better would be to use solid carbide drills. And if some kind of coated, it will speed things up also.

The bit you link to seems ok. At least the tip and the flutes angle. Don't know about their quality

Robin Hewitt
23-09-2016, 10:17 AM
In days of yore when I learnt this stuff the general rule was that you used the same tools for brass as you did for iron, but your brass set was only ever used to cut brass. Mind you, brass was horrible back then and used to snatch given the slightest provocation.

23-09-2016, 06:44 PM
Hi Boyan, thank you, a very informative thread. It is amazing how fast you can drill these holes! My converted CNC mill is limited to 9000 rpm and I will adjust to that.

I think I just try out the drill bit I have linked to. I can buy them for 5.35 through the company I work for, so it's not that much. The Format brand seems to be quite reputable, so I don't have big concerns with the quality.

I just want to mention that I don't actually buy stuff through the company, I just make "small" jobs now and then on my RF-45 and they pay me with tools and material. I like that very much, because then I can do my hobby and get a lot of good quality tools for "free" and they will always come in handy for other jobs :-)

This job though, is for a different customer and my first series production. This is the reason I ask for help, because it certainly has great impact on choosing the right tool for the job when doing series production and I just wanted to hear if there was a better alternative.