View Full Version : Ignoring those warning signs:

02-06-2010, 11:05 PM
The other morning I was making a part on the lathe that needed a hole tapped. The tap drill was an “I”. I got out a set of letter drills and a tug of war started. I couldn’t get the darn thing out of the metal box. Drills on either side slid out normally. Finally resorted to some fairly serious persuasion and it came out. Drilled the hole to be tapped and installed the tap in the tailstock and it slid to the bottom of the hole without touching anything. Turned out they gave me two “K” drills and that was why it was so tight to get out of the box. Fortunately this was a simple piece and it didn’t take long to redo it. Ignoring those warning signs will get you ever time.

02-06-2010, 11:18 PM
Yep, I have had the same thing happen. I also got a set once with some of the drills in the wrong holes, numbered in lettered, etc, etc. Now when I buy a set of drills or anything I check to be sure it's a full set and everything is in the right place.

Something like that can ruin your day.

02-07-2010, 12:00 AM
You only do that stuff once.
When my apprentice looks at me wrong when I mic EVERY drill I use, I remind myself why I do it.


02-07-2010, 05:34 AM
The difference between an I and a K is only .009", what thread were you trying to tap?

02-07-2010, 08:33 AM
:D and I thought I was the only one that checked a drill with calipers on an important hole. I have a block of plastic with the tap and corresponding drill in it. Well, somehow two drills got switched and I drilled an oversize hole. I wondered why the tap went in so easy and measured the drill :eek: what the heck. Now unless the difference is obvious I measure them too.

I found it easier to measure with the drill parallel to the jaws of the calipers.

02-07-2010, 08:59 AM
The difference between an I and a K is only .009", what thread were you trying to tap?

Thats what I was thinking, sometimes I use the next drill size on purpose for hard metal.

I have had drills get stuck when they get a little bur on them from the chuck.

02-07-2010, 09:15 AM
Yea, I hate filing off that damn burr too. the chuck finaly found something to hold onto and now I gotta remove it? dang.