[doodlebug]

ps. 3rd broken tap. 3mm is a nightmare to tap apparently due to size. at 8$ each it gets old fast. i am not getting any chip clearing really, so i have to back in and out little by little till its all threaded in. each time clean the debris out of the hole. if you go a hair too deep at once it snaps, usually on the counterspin.. blind holes, no issue with through holes.
What size tap drill are you using? look at your chart, go for 80% or less thread's, to help prevent the tap's from binding and breaking. Hopefully the pro's will chime in on this!
Cheer's, Neil.