Customer Reviews for Drill America 1/2 in. x 12 in. Cobalt Aircraft Extension Drill Bit
- For tough, high tensile strength materials like stainless steel
- 135° split point tip prevents drill from walking
- 12 in. L for drilling where extra length for reach is required
Customer Reviews
Apr 11, 2019
This is an accurate bit especially for a small diameter in this length. I was most impressed that...
This is an accurate bit especially for a small diameter in this length. I was most impressed that the bit does not walk around on the material. I would not utilize this bit on 3/16 flat stock as depicted in the photos and video: however, for the sake of the review, I demonstrated this bit and it’s accuracy on some tough material. I do strongly recommend!
by BrownBuilt
Apr 6, 2019
When you need that extra long drill bit to go through hard materials, this is the one you need. ...
When you need that extra long drill bit to go through hard materials, this is the one you need. Although it is made for metal i have used it for a number of things including drilling through my enclosed trailer so I could add some wiring and it worked perfect. the bit is sharp and makes quick work of going though areas that you need a longer reach. The composite of the bit seems very strong and didn't bend or flex while I was drilling through the a metal frame of a desk.
by JackinNH
Apr 2, 2019
This cobalt steel bit easily drilled through 3/16 inch steel (ten rapidly drilled holes) with no degradation to the drill bit nor imperfections in the drilled holes. The bit comes in a protective plastic case which will minimize the chances of being damaged in one’s tool box. It is long and slender (12 inches overall, 2 ¼ inch fluted section), thus care must be taken to not apply too much pressure (to prevent “bowing”), however even with minimal drilling pressure, it made clean holes quickly and did not tend to “wander” when started without centerpunching first. With proper care this bit should exhibit a reasonably long life.
by DonK
Mar 25, 2019
It's difficult to write a review about a drill bit because they either work... or they don't. I r...
It's difficult to write a review about a drill bit because they either work... or they don't. I really wanted this particular size bit because of it's 12" length which makes it well suited for drilling through exterior walls. It's only 3/16" in diameter though so you have to follow it up with a larger bit if you're running anything substantial but have a pre-drilled hole means you can drill from both sides with a larger bit and meet in the middle easily. The spiral runs a about 2 5/8" down the shank. This bit is great for drilling through wood, but using it to go through steel will probably dull it in short order. Softer metals shouldn't present too much of an issue. As with all drill bit the drill diameter is engraved into the bottom end of the shank but it is a little tough to read.
The only improvement I could see them making would be to machine the shank at the last inch or so, so it can be more securely gripped by the drill chuck. This came to me inside a blue plastic sleeve that I an continue to use for storage.
by
Mar 25, 2019
The 3/16" x 12" Colbalt Aircraft Extension drillbit works great to use when you need to drill int...
The 3/16" x 12" Colbalt Aircraft Extension drillbit works great to use when you need to drill into hard to reach areas. I use this 3/16" bit to drill pilot holes for screws. It is a high quality bit that I can drill a lot of holes in sheet metal before it needs sharping. It comes with a square plastic container to store the bit in when not being used.
by Lucky
Mar 23, 2019
Depending on what I need to drill through I sometimes like to drill a smaller pilot whole before I drill with the big bit. This does that for me. I also need to drill through a support beam that has a piece of ¼” plate sandwiched between the 2 x wood beams. I needed to install a dryer vent through the side of the house, I used this bit to drill a pilot hole before I used the large hole saw from the inside then outside. This handled both fine. I would recommend this for what is was designed for.
by HomeDepotCustomer
Mar 20, 2019
This 3/16 inch diameter 12 inch cobalt aircraft extension drill bit by Drill America has more cob...
This 3/16 inch diameter 12 inch cobalt aircraft extension drill bit by Drill America has more cobalt so that it has good performance when cutting harder metals such as stainless steel or nickel alloys. It has a Gold oxide surface treatment rather than black oxide typically used, so performance is very good. It comes in a nice case (see picture). The 135° split point is self-centering and reduces thrust (see picture). It is always great to have a smaller diameter, longer length drill bit like this one when you need to pass smaller diameter wires without making a gaping hole that will need to be back-filled to prevent bug or rodent incursion. I highly recommend this drill bit!
by DickB
Oct 8, 2018
I've got almost every size drill bit under sun, but very few with any length to them. It's one of...
I've got almost every size drill bit under sun, but very few with any length to them. It's one of those things, that for me at least, is rarely needed but when you do need it there is no good substitute. This seems like a very high quality bit and even visually looks much nicer than your standard high speed bit. Needing to get through 1/2 siding, 3" steel tubing, and another 5/8" plywood all sandwiched together worked out great with this bit while drilling multiple mounting holes for new latch hardware on my shed. Thumbs up.
by DstBstSN
Sep 29, 2018
The drill is a full 12" long, but the cutting flutes are only about 2 1/2" long, so when you are ...
The drill is a full 12" long, but the cutting flutes are only about 2 1/2" long, so when you are deep plunging your work piece, there is no path for shavings, heat or expansion to escape. If you make very light plunges, and back out often, you can get the work done. This drill had a hard time drilling through a piece of cedar, I wonder how it would handle metal.
by CharlieW
Aug 20, 2018
AWESOME drill bit! I have been needing one of these for longer than I realized. If you need to d...
AWESOME drill bit!
I have been needing one of these for longer than I realized. If you need to drill a hole, in a place that you just cannot get to, this is it.
The only other option is to use a drill bit extender, and they are not as convenient as having ONE long bit.
I needed to drill a hole through the firewall on my car to run some accy wires, where I just could not reach, and another through the floor under the kitchen, to run a water tap for the fridge.
This long bit did both with ease!
by BadgerJack