Posthole Digger Advise on Post Hole Digger Auger Size

Redbug · Jun 1, 2008

I plan to buy a Leinbach 3 point hitch post hole digger in the near future. I know the model I want, (L-7200), but am not sure about the auger size I should get when I get it. It will take 4, 6, 9, and 12 inch augers. I plan on using it to dig holes for fence posts and most likely a pole barn, too. I was leaning toward the 9 inch. What do you recommend?

teg · Jun 1, 2008

I was thinking of a 9" but ended up with a 12"... mainly using it for planting trees and cabin posts. Figured it is easier to fill in then to dig larger. The points on those augers could be better built (longer). I have some parts and an idea

I bought the L-7200 from the Leinbach store, $370 +/- and got extra shear bolts. I have rocks and roots... I also picked up a 36" pipe wrench from Agri-supply for $20, cheap but works if you have to un-screw an auger. Only used it once but it took one minute to free an auger that drilled itself into the ground.

homeinwestIL · Jun 1, 2008

I'm using a 9-inch on my fence post holes, using 4x4 posts. You need to line it up carefully to make sure it's straight. I've had to do some digging in a few but with care, the 9-inch works fine. The 12-inch would give you more room for error but require more fill to set the post. If (or when) I get around to building my pole barn, I think I'll get a 12-inch because I expect I'll be using 6x6 posts. I guess it depends on what size posts you're using.

Jim-Satoh · Jun 1, 2008

Hey Guys--how much would it sat me back to buy a post hole auger complete, probably about a 3-6 inch size. My Satoh has a 3 pto and the drive shaft, but thats all, no hook up for a auger. I guess you need the boom plus auger.

jjmarotz · Jun 1, 2008

My L-7300 has the 12" auger and I found it is nice for the leeway and extra room to level posts as others stated, but, when my uncle uses it, it is too big for setting concrete sonna (sp) tubes for concrete. Would be nice to have the 12 and a 6 or 9, for certain jobs.

teg · Jun 2, 2008

Jim-Satoh said:
Hey Guys--how much would it sat me back to buy a post hole auger complete, probably about a 3-6 inch size. My Satoh has a 3 pto and the drive shaft, but thats all, no hook up for a auger. I guess you need the boom plus auger.

The drive shaft for a post hole digger is very long and not very common. You'll also need the gear box which makes the 90* turn from the pto drive shaft to the auger... basically, you'll need a complete unit, around $400-$600??? What I've seen, the 6" auger and the 9" are the same price, 12" is another $10-15 more.

Jim-Satoh · Jun 2, 2008

teg said:
The drive shaft for a post hole digger is very long and not very common. You'll also need the gear box which makes the 90* turn from the pto drive shaft to the auger... basically, you'll need a complete unit, around $400-$600??? What I've seen, the 6" auger and the 9" are the same price, 12" is another $10-15 more.

Thanks for the information. My land is clay and rock. Manual post hole diggers is a job.

Fug1000 · Jun 2, 2008

It's worth it..and more.

Some folks will argue that a backhoe is the way to go and if you have more digging to do than just simple "holes" they are correct.

But if you are simply planting trees or putting in a fence, a PHD gives you the most bang for your buck.

I also opted for a 12inch blade for the extra 'wiggle room' and small tree planting.

I also got me a 24inch bit. Talk about a beast. It takes some effort to get a 2 or 3 foot hole with a 24 inch bit but it can be done.

I planted almost 50 trees with my 24 inch bit last year.

skipmarcy · Jun 3, 2008

My Leinbach has been a good one. I have a 6" and a 12" auger and those 2 sizes will handle most any kind of post I'll ever put in. The Leinbach uses what seems to be a common size output shaft and bolt hole spacing - several different brands of augers will fit it. Get the size auger you need for now and you can buy another for $100 - $125 later when you really have to have it. It really takes practice learning to use a PHD. The key is to keep your PTO speed low and clear your hole out as you go by pulling the auger up quickly to sling the dirt out off the flites - you have to stop the lift before the auger comes out of the hole - you need to be good with your hitch control. I run my throttle up to about 1100 - 1200 rpms for operating my digger. Good luck on your new equipment !!

Redbug · Jun 4, 2008

Thanks for the advise. After reading the posts and really good advise, I think I will get the 6" and 12". Didn't really think of getting both, but after Skip's post and thinking about it some more, that would be the most versatile setup in the long run. What the heck...it's only money...