Posthole Digger Post Hole Digger - Auger Size?

   / Post Hole Digger - Auger Size? #1  

truejourney

New member
Joined
Aug 29, 2000
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20
Location
East Central Ohio
Tractor
Kubota B2710
I am planning on purchasing a PHD from Tractor Supply and am looking for advice as to what size auger to get. My initial use will be to install both high tensile fence and field fence - 4" to 6" post sizes. Eventual plans are to install a pole building so that may require an additional auger. Any suggestions, experience, comments, and such are appreciated. My tractor is a Kubota B-2710.
 
   / Post Hole Digger - Auger Size? #2  
Are the posts you listed sizes for square or round?

For square posts 4x4 (5" across the diagonal) a 9" auger works nice. For a 6x6 (7.75" across the diagonal) a 12" auger works nice. You want to have some extra room to allow for the auger to walk off a little during drilling. Then when you set the post you have a couple of inches all around to adjust the post to the straight line. Too much extra hole just means more time back filling. Like everything else, having the right tool for the job can make a big difference so you may want to have more than 1 auger size.

Jeff
 
   / Post Hole Digger - Auger Size? #3  
I bought a PHD from Tractor supply last year and it works great. I have a 9" auger and probably drilled about 90 holes with it.
 

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   / Post Hole Digger - Auger Size? #4  
How good are you?

Myself, I bought a 9" and 14" auger with my PHD. Simply because bigger offers more chance to be off a bit, and still get the posts in line.

The 14" was mainly intended for setting 6x6 posts for my tractor shed. I put 12" diameter concrete stones in the bottoms of the holes to set the posts on, so I needed something larger than 12" so I could be sure to be able to drop those stones in. Fact of the matter is, that the hole always seems larger than the auger...a 12" might have been good enough...

Putting dirt back in is so much easier than taking it out, that I have never minded a larger than necessary hole, when the PHD does the work. Guess I still remember using a digging bar and hand operated PHD too well... /forums/images/graemlins/crazy.gif

I would say if your are going to be putting in 6" posts and want to end up with things in a straight line, get nothing less than a 9" inch auger...
 
   / Post Hole Digger - Auger Size? #5  
I have a TSC phd and a 2910, so my equipment situation is similar. My place has a lot of rocks and gravel. I find that the 9" auger will drill through the packed gravel/cobble pretty easily, and the shear bolt won't break very easily. With the 12" auger, it will often quit drilling down, and the shear bolt is much easier to break.

I drilled about 40 12" holes at a friend's house that was strictly black dirt. Only sheared a bolt a couple of times in this instance.

But I grab the 9" auger if at all possible. I think for the post size you are talking about, it is the best choice.
 
   / Post Hole Digger - Auger Size? #6  
I've got a 6" bit for my Bobcat auger. I have been putting up quite a bit of high-tensile fencing lately. I put in 1200' 48" high fencing along the front of my property using 4"-5" line posts and 5"-6" end posts.

My auger is self-leveling, so I am able to drill a pretty straight hole. The 6" posts were a tight fit, but were level. The advantage to the 6" auger is the less tamping that needs to be done.

I am currently working on fencing in a 3 acre section with 6' high fencing. This will have 8-wires and I hope it is good enough to keep out the deer. I will be planting trees into 12" grow bags this fall. I have been very happy with the 6" bit -- I'm sure a 9" bit would have worked just as well.
 
   / Post Hole Digger - Auger Size? #7  
I've got a Post Hole Digger from TSC and have been very happy with it. I own a 6" and recently purchased the 9" auger. I've found the 6" to work just fine for drilling 4x4 posts, but you've gotta drill-em straight. I use the 9" for new tree holes. There's a big difference between the 6" and 9".... Based on your requirements, I would go with the 9". You can always tamp dirt back in around the 4x4 posts.

Henry
 
   / Post Hole Digger - Auger Size? #8  
</font><font color="blue" class="small">( I own a 6" and recently purchased the 9" auger. I've found the 6" to work just fine for drilling 4x4 posts, but you've gotta drill-em straight. I use the 9" for new tree holes. Henry )</font> <font color="blue"> </font>

Any suggestion on how to drill-em straight?

How deep do you do your tree holes?

David
 
   / Post Hole Digger - Auger Size? #9  
<font color="red"> Any suggestion on how to drill-em straight?
</font>
Practice, practice, practice... and for those of us who still can't do it, we use a bigger auger bit so we have some wiggle room.

<font color="green"> How deep do you do your tree holes? </font>

I dig mine as far down as the auger will go, then I mix in compost with the spoils that the auger throws out of the hole. I refill the bottom of the hole up to the level of where the tree or bush should be planted.
 
   / Post Hole Digger - Auger Size? #10  
I have a 12 inch auger and have no experience with any other size. So with that knowledge, I'd say get the biggest size auger your tractor can handle.

You can spend all the time in the world lining up your holes, getting everything perfectly strait, and six inches down you hit a rock or root and off goes your hole. I guranttee it will happen almost half the time.

Like Henro said, its easier to put the dirt back in, than to dig it out by hand. Especially when your putting in a straight fence that has to be perfect. Plan on lots of hand digging even with a 12 inch auger.

No insult meant for those with smaller augers, but I feel you are working way too hard to get a hole in the ground that you have to back fill anyway, and I think I can get better compaction with some space around the post than worrying about air pockets and such in a smaller hole.
 
 
 
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