Dull drill bits - throw them out

[mayhemscout1519]

Sanddrag, sorry to hear about your accident but in light of the situation, I'm glad it sounds like you will make a full recovery - hopefully it's a speedy one!

One thing I have noticed while working in shops (and many other areas in life, in fact) is that when you are operating big tools or doing dangerous things, or at least tasks perceived as dangerous, you get your "guard up", and begin to really think each task through and just generally be very careful. It's when doing those mundane tasks that we've done a thousand times, like drilling holes, that we're actually more likely to get hurt! It's because of the simple fact that when doing mundane tasks, we don't have our guard up because the task is perceived as easy or simple because we've done it so frequently. We must try to keep our guard up at all times, thinking about how to prevent injury, or what would happen if x-y-or-z happened, or consider plan B, or have an "out route".

Sadly, it often takes an accident or injury such as yours to reminds ourselves and others that a "simple" task such as drilling a hole can quickly turn into a very dangerous situation. So, hopefully your accident can be a lesson to others on your team and here on Chief Delphi. Again, hope you experience a complete and speedy recovery!

[Daniel_LaFleur]

Originally Posted by mayhemscout1519

Sanddrag, sorry to hear about your accident but in light of the situation, I'm glad it sounds like you will make a full recovery - hopefully it's a speedy one!

One thing I have noticed while working in shops (and many other areas in life, in fact) is that when you are operating big tools or doing dangerous things, or at least tasks perceived as dangerous, you get your "guard up", and begin to really think each task through and just generally be very careful. It's when doing those mundane tasks that we've done a thousand times, like drilling holes, that we're actually more likely to get hurt! It's because of the simple fact that when doing mundane tasks, we don't have our guard up because the task is perceived as easy or simple because we've done it so frequently. We must try to keep our guard up at all times, thinking about how to prevent injury, or what would happen if x-y-or-z happened, or consider plan B, or have an "out route".

Sadly, it often takes an accident or injury such as yours to reminds ourselves and others that a "simple" task such as drilling a hole can quickly turn into a very dangerous situation. So, hopefully your accident can be a lesson to others on your team and here on Chief Delphi. Again, hope you experience a complete and speedy recovery!

Quoted for truth.

When the job at hand gets to be more of a habit than safety on the job, thats when people get hurt.

Make safety a habit.

//Sandrag, Glad to hear that your 'learning experiance' was fairly minor. //

[Wayne Doenges]

Sandrag, I'm glad you were not mangled too much

Soemthimes I ask the students what is more dangerous, a sharp knife or a dull one? The dull one is more dangerous as you have to put more effort into using it

[Racer26]

Originally Posted by Daniel_LaFleur

Quoted for truth.

When the job at hand gets to be more of a habit than safety on the job, thats when people get hurt.

Make safety a habit.

//Sandrag, Glad to hear that your 'learning experiance' was fairly minor. //

When we've done things hundreds of times, we get complacent. Complacency is one of the biggest things that flies in the face of safety. We must be vigilant.

It is also 100% true that a less-than-stellarly maintained tool (a less-than sharp drill bit, knife, whatever) is FAR less safe than a sharp one.

You're alot more likely to complete the job safely if you're not putting alot of load on the tool.

[My-smokepole]

Sorry to here about you getting hurt. At the same time if you learn how to sharpen them. By hand on a fine belt sander it is a live learn skill. And Any live learn skill is worth the time. I agree that at somepoint it is cheaper to get new. Somewhere down where I can't see the tip.

[travis]

In thin gauge Al, I start every hole with a #40. This is not only the smallest practical bit in my opinion, it is also the hole size for a 3/32 rivet (and the associated cleco clamp).

The middle of your standard 118° chisel point twist drill does not so much cut, as mush metal out of the way. The chisel point is also the first part of the bit to dull. The only bit that has to do difficult center cutting is the pilot, so you might as well use a small one to limit the force required. After that you can generally chase the hole with your desired drill. If you are drilling a particularly big hole, measure the web thickness of your finish bit, and select an intermediate bit that is larger. This wil ensure that only the best cutting geometry of your bit is put into service. This can be a little chattery with a hand drill, but takes less dangerous effort.

Drill sets are a waste of money and space (I bet you use that M bit 50 times a day). If you design your own robot, you can keep fastener type count down, and only need a few bit sizes.

My bit of choice for hand drilling Al is jobber's length, 135° split point, HSS, bright finish. HSS is less brittle than cobalt and plenty hard and heat resistant for Al. Bright finish (no coating, just polished) is fine at preventing chip welding in Al, much better than any import-grade coating. The split point helps with wandering, but if you start with a #40, you almost don't even need to center punch. That configuration is also about the cheapest there is, so buy from a nice name brand made in USA/Switzerland company and get a zillion #40s. Good tooling doesn't cost money, it makes money (and prevents doctor visits).

If you are still breaking bits, get a faster drill, like a <=3/8 chuck air drill, which is also lighter and easier to control. The recommended RPM for drilling an 1/8" hole in Al is about 12KRPM, or around 5 times faster than your average battery powered drill. Screw length bits are about half as long as jobbers, and thus less likely to snap in twain.

travis "drillbit" taylor