Garden auger bits - what drill is suitable?

[pstq]

What drills are suitable for these garden augers?

https://www.bunnings.com.au/sutton-tools-50-x-450mm-garden-auger_p0139207

Do they need to be very powerful? I've got a big 850W Ozito SDS+ drill (with normal chuck adapter), but it doesn't have speed control. Do they have to be able to run slow? I need to dig some holes for deck stumps in heavy clay, and I thought something like this might be good to start the holes off before I start digging by hand. Not much room under there for a full sized auger.

I thought the 50mm might be best because it would be less likely to wrench my hands if it jams. Just drill more holes instead of using a big one.

[EricL]

Hello @pstq

Thanks for sharing your question about the Sutton Tools 50 x 450mm Garden Auger. The Garden Augers shaft diameter is 7/16 inch which is equivalent to 11mm in metric. You will need a drill with a chuck allowance of at least 13mm. Your 850W Ozito's should be perfect for the job. 

Because you are drilling into clay or soil that has a lot of clay in it. Your drill will not only have to be powerful but be able to operate at a slow speed delivering tremendous torque. I suggest drilling on the surface first but not plunging the drill deep into the soil to prevent it from getting stuck.

Let me tag our experienced members @Adam_W and @ProjectPete for their recommendations.

If you need further assistance, please let us know.

Eric

[pstq]

I got the 50mm auger, and it seems to work ok in the clay with my cordless drill (Ryobi RCD1802), but I don't think it could handle the 75mm. I haven't tried it with the Ozito yet, but I'm wondering if it'll be a bit fast - 800rpm vs the Ryobi's 440rpm.

[MitchellMc]

Does your Ozito drill not have a variable speed via the trigger, @pstq? The more you pull the trigger, the faster it goes?

Mitchell

[pstq]

No, it's stop or go. I bought it to use as a mini jack hammer, and for tough concrete drilling jobs. It's good for those.

[pstq]

I tried it in the Ozito. It worked well, but I also didn't realise it has no reverse, so I have to heave it out of the hole still running forwards. It chatters when I do that, it must engage the hammer mechanism. I think if I hit a rock and jammed it, it might be hard to get it back out without reverse.

I also tried it with a smaller GMC drill. That has variable speed and reverse, so works ok.

[EricL]

Hi @pstq

Thanks for posting the results of that experiment. I'm sure this information will prove handy to those members who are thinking of drilling into clay soil. My primary concern was the drill getting well and truly stuck into the clay soil with no option for reverse. I'm glad you were able to pull it out of there. I suspect that if it did hit a rock, you would be spending a great deal of time trying to get unstuck rather than making progress with your project.

Please keep us updated with your progress, we look forward to seeing the stump holes dug out and ready for use.

If you need further assistance, please let us know.

Eric