Uni-bit to the rescue!

mikey

mikey

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Staff member
Rest In Peace
I drilled some holes with a "K" drill on the edge of a 1" thick steel plate today. These were to be tapped for a 5/16-18 thread. Problem was that the plate was 1' wide X 2' long and I couldn't fit it comfortably on the drill press or the mill so I had to hand drill these holes. I stood the plate on edge, clamped it to a sturdy wooden shop stool and spotted and drilled a pilot hole. Ordinarily, you do not need to chamfer the pilot hole; you can just follow up with the main drill. BUT when using a hand held drill the bit can tip in an unpredictable fashion and both flutes of the drill may not bite evenly. This produces a stuck drill and two relatively huge chips sticking into the middle of your stupid hole!

Now, you can break those chips off but the drill will be damaged when it jams again. Or you can break the chips off and use a carbide burr to grind the area down so the drill has a chance to go in clean, which it usually doesn't do; it just jams and raises two new burrs! How do I know these events will happen? Yeah, I admit it. I tried it and failed. I've been drilling holes for most of my life and have had this happen only a few times but as I am a member of this forum and have been known to embarrass myself here, I thought I would share the fix.

I took a Uni-bit, the kind with the multiple steps, and simply drilled down past the chipped area. This eliminated the surface defects and made a nice new chamfer for my drill bit to start on and the drill went right in. Twice. Yeah, I messed up two holes and the Uni-bit saved my bacon. It worked so well that I was surprised, both at how well it worked and at how I never thought of using a Uni-bit for this before.

I suspect jamming a drill like this is something that mostly happens when using a hand-held drill but if it happens to you, remember the Uni-bit!
 
Nice save! I love Unibits, although most of mine are imports. My only actual real Unibit has seen it's better days. I always keep one in my drill or nut driver tool bag just in case.

Step drill saved my butt when I was installing hood struts on my truck. The brackets are supposed to install with pop rivets & sheet metal screws. I didn't like that & choose to use rivnuts. I quickly figured out why they use pop rivets & sheet metal screws, no room for error & can easyily be SOL if not precise. I won't explain all the details but a step drill saved the day for one problematic hole that would have been fubar'd if I didn't take a moment to rethink what to do.

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Glad it saved you, too! I am guilty of under-appreciating this tool but I will not forget this lesson.

I have one Irwin Unibit and two Lenox versions and I'm convinced that the Irwin tool is vastly superior, both in performance and longevity. I'm usually a Lenox fan but for Unibits, buy Irwin.
 
My Unibit is an Irwin also. It still cuts but it's not that sharp any more. I have noticed that it has lasted waaaaay longer than the imports I have but that's to be expected, I definitely got my money's worth out of it. But with the imports I don't have to worry about beating them up or loosing them if out somewhere, cheap to replace. Only reason why I bought imports is cause I wanted various sizes, the real Unibits are pretty pricey! I'll buy another Irwin someday. :big grin:

I'm a Lenox fan too, all my bandsaw blades are Lenox.
 
It seems about every other month, Harbor Freight sells the 3 piece step bit sets for about $9, if you an inside track member. When on sale, I usually buy 5-6 sets, and use them brutally. I used one bit to open up (205) 1/2” holes up to 3/4”, in 3/16” steel, using a cordless Milwaukee drill, on the low setting. The last 5-6 holes were a bit of a challenge, but the bit finished the job, then came out of the drill, right into the dumpster, a cheap solution.
 
I have a Milwaukee set and they work great. The steps are not deep though so you are a bit limited with depth of material that they can be used on. If enlarging a hole in plate or bar stock and if you can flip the piece then you can work with thicker material.
 
mikey said:
I drilled some holes with a "K" drill on the edge of a 1" thick steel plate today. These were to be tapped for a 5/16-18 thread. Problem was that the plate was 1' wide X 2' long and I couldn't fit it comfortably on the drill press or the mill so I had to hand drill these holes. I stood the plate on edge, clamped it to a sturdy wooden shop stool and spotted and drilled a pilot hole. Ordinarily, you do not need to chamfer the pilot hole; you can just follow up with the main drill. BUT when using a hand held drill the bit can tip in an unpredictable fashion and both flutes of the drill may not bite evenly. This produces a stuck drill and two relatively huge chips sticking into the middle of your stupid hole!

Now, you can break those chips off but the drill will be damaged when it jams again. Or you can break the chips off and use a carbide burr to grind the area down so the drill has a chance to go in clean, which it usually doesn't do; it just jams and raises two new burrs! How do I know these events will happen? Yeah, I admit it. I tried it and failed. I've been drilling holes for most of my life and have had this happen only a few times but as I am a member of this forum and have been known to embarrass myself here, I thought I would share the fix.

I took a Uni-bit, the kind with the multiple steps, and simply drilled down past the chipped area. This eliminated the surface defects and made a nice new chamfer for my drill bit to start on and the drill went right in. Twice. Yeah, I messed up two holes and the Uni-bit saved my bacon. It worked so well that I was surprised, both at how well it worked and at how I never thought of using a Uni-bit for this before.

I suspect jamming a drill like this is something that mostly happens when using a hand-held drill but if it happens to you, remember the Uni-bit!
Click to expand...
Mikey, help me understand why you couldn’t put the steel chunk in your mill vise? Help?
 
It seems to me that I probably would have moved the mill vise and just held the steel chunk on the table like normal. I so much hate hand drilling bigger holes, and I would much rather use the mill than the drill press. That's how weird I am.
 
mikey said:
The plate was 1' wide and 2' long. Too big to fit in a vise.
Click to expand...
Duh! 1 foot by 2 foot.....when I first read it I saw inches....could you have set it up and secured it to the mill table? I get it was a bit wide.....
 
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