Century Drill & Tool – 38113 12” Ship Auger Extension – Accepts 1/2” Shank, ½” Hex Drive with Extended Reach

Ordered wrong, but kept for future use maybe. Looks well built.

Exactly the tool I needed for extended reach. No faults.

Four stars because does not work without a modification. I was worried when I read the other bad reviews, but I had no other alternative for the task at hand. So I bought this extender, and rather than risk the drill bit spinning around in the extender because the set screws would probably not secure the bit under the punishing drilling I was about to do, I decided to modify my bit. I flattened the 2-1/4" Forstner bit shank in the two spots the set screws would touch in the hopes that so doing would keep it secure. It worked! I drilled a hardwood, 3-1/2" log, 12" down the center - that's along/with the grain - not across the grain. The first 3 to 4 inches I did without the extender, but I had to use the extender to make the turn/follow the bend, and that alone took a half hour to go the last 8-9" after the bend. Flattening the shank for the set screws like I did, held just fine. P.s. The drill bit metal was so hard, a hand mill file did nothing to it, so I got out the Dremel with a chainsaw sharpening grinder attachment, and that did the job handily (and the bit still works just fine in a chuck). See the photos...

It's long but you can always shorten it.

I bought the 12" extension with 1/2" hex to 3/8" shank. It is very heavy duty. It works with my Irwin Forstner Bits.The round 3/8" shank of the Forstner Bits fits extremely snug. I had to put the face of the bit on a piece of wood and hit the extension with a dead blow hammer to get it to seat fully. I could've lightly sanded the Forstner bit shank to make it easier to insert but I figured using the hammer would be quicker.I did not grind a flat spot on the Forstner bit shank for the set screws like other reviewers said that they did. I just tightened them and it held fine.I used a 2" Forstner bit with the extension to drill a vertical hole in the center of a large stump and a 2nd horizontal hole from the side that connects to the bottom of the vertical hole. I pre-drilled the holes with a 3/8"x17" auger bit before using the Forstner bit.I'm going to burn the stump by starting a fire in the vertical hole and use a leaf blower in the horizontal hole.

The bot holder end it 1/2" round - not Hex which is just what I wanted. I have a 3" Forstner bit I need to drill through a 10" beam and the bit has a 1/2" round base so this is just what I need. The bit extender base is a hex that you chuck into a 1/2 drill. I am happy with the purchase.

This extension bit was badly milled. There was a tiny bur/bead of metal inside between the 2 set screw holes that wouldn't allow my 3/8" shank to seat all the way past both set screws. In my attached pic, you can see the bead on the inside. As best I could tell, it wrapped about halfway around inside. I called Century Tools and they said it was likely a milling/manufacturing error and to just return it to where I bought it. Well, kudos to them for at least answering the phone and talking to me but one star for their quality control. I searched around a bit for other options and it became clear that the 12" extension/3/8" shaft wasn't easy to find and I specifically had to have this for a project. Like another poster, I have a drill press and cobalt (metal drilling) bits so I squared everything up and drilled the bead out myself - but I shouldn't have had to do this. It works great now and the shank of my bit sits down past both set screws securely. If this extension bit is your only option just be prepared in the event you might need to do your own fix.

Nice extension with Allen screws to hold bit in place .