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This maybe a dumb question but I simply want to make sure I got it right because the manual seems to be defective. I already got one of my drill bits ruined.

So, could anyone show me both pictures of a left-handed drill bit and a right-handed drill bit (because I'm not sure which I'm using) and what direction should they rotate for each to drill forward assuming that the user is facing the tip of the drill bit? (e.g. clockwise or counterclockwise when facing the tip of the drill bit).

When I say tip of the drill bit, I mean the end of the drill bit that makes contact to the surface to make holes.

Please forgive my English.

UPDATE:

Here's the picture of my power drill and the manual.

enter image description here enter image description here enter image description here enter image description here enter image description here

As you can see in the picture it is currently set to "R" which turns, as the manual says, the drill bit to the right or clockwise. I'm assuming the manual meant that from the perspective when the drill bit is facing you as shown in the image from the manual. It actually does that. So from my perspective behind the drill it's rotating counterclockwise. As written in the manual, you have to set it to "R" if you want to drill forward and "L" if you want to reverse drill.

Update:

And the video http://vimeo.com/m/64855403

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The manual is correct, you're thinking backwards. Clockwise and counterclockwise is from the perspective of you behind the drill -- That is, how you would normally hold it, looking down on the work. That being said, most drills use F and R, for forward and reverse, or have little arrows on the switch. Bad User Interface design in my opinion. –  Chris Cudmore Apr 23 '13 at 16:59
    
R is the same as right, forward or clockwise. I have never seen a reverse drill or left handed drill bit. –  Roscoe Apr 23 '13 at 19:07
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"Righty, tighty. Lefty, loosy" –  DA01 Apr 23 '13 at 19:40
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See the edit to my answer. I've added an image of the drill in action with clearly indicated clockwise/forward. –  Chris Cudmore Apr 24 '13 at 13:22
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@supertonsky: Yeap, the manual is right (and the drawings in it are correct), but the drill case has letters R and L swapped. Excellent video btw. –  sharptooth Apr 26 '13 at 6:36
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4 Answers

up vote 7 down vote accepted

Think back to your high school physics class and use the Right Hand Rule.

Lay the drill bit across your palm, with the point towards your thumb. If the fingers curl around the bit (or screw) in the direction of the threads, then it's a right handed bit. That means you turn clockwise to drill (from the perspective of looking down on the work).

enter image description here

This rule is also extremely helpful when you are working upside down and backwards trying to tighten something. Point your right thumb in the direction you want the screw or nut to travel, and turn the object in the direction your fingers curl to tighten.

When in action, Clockwise/Forward looks like this.

enter image description here

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I don't understand your use of the "right hand rule". How are your fingers "in the direction of the threads"? Couldn't you put that same bit in your left hand and say the same thing? Your second statement, about pointing your thumb in the direction of travel, makes more sense. –  Henry Jackson Apr 26 '13 at 4:48
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Here is your asked for "end on view" of a drill bit with the cutting edges and direction of rotation indicated. This shows the "normal type" of drill bit that you would find for most applications.

enter image description here

You also asked for an "end on" picture of the non-standard type of drill bit that operates in the opposite direction. Those likely do exist out in the wild world of the machine shop but I have provided that through the magic of a flipped video image. So the following would be the picture for a "left handed" drill bit.

enter image description here

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TL;DR; almost all drilling bits have to be rotated clockwise to achieve drilling and sometimes you will need to rotate them counter-clockwise when they stuck in the material and you want to extract them easier. I've never seen a drill bit that has to be rotated counter-clockwise for drilling.

When you look at a drilling bit you'll see it has grooves which more or less resemble grooves on a threaded part like a screw or a bolt. The same way you identify an X-threaded (usually right-threaded) screw you can identify an "X-threaded" (usually "right-threaded") drilling bit - the grooves will be oriented the same way. If you have a "right-threaded" (actually "right-grooved") drilling bit it has to be rotated clockwise to achieve drilling.

Here's an example (original from Wikipedia, I rotated it and added an arrow showing how to rotate the bit to achieve drilling). This is a "right-grooved" (most typical) bit, it has to be rotated clockwise.

enter image description here

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I have never in 50 years seen a counter clockwise drill bit. All bits drill clockwise. –  shirlock homes Apr 22 '13 at 9:51
    
@shirlockhomes: This section even has a photo: en.wikipedia.org/wiki/Twist_drill#Left-hand_bit –  sharptooth Apr 22 '13 at 9:53
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Don't worry about clockwise or counter-clockwise - instead, just examine the drill bit turning at a slow rotation. A bit is designed to remove the drilled material as it turns. When drilling a hole, make sure that the grooves are turning so that material will be ejected from the hole. This will also tend to pull the bit into the material. You can also visualize the bit as a screw to know what direction to turn.

Along the same lines, the chuck will turn in a direction that tightens when drilling into a material.

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AKA use your common sense. I got that but got confused when I saw the manual that says otherwise. –  supertonsky Apr 24 '13 at 4:00
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