How Much PTO HP is needed for an 18" Auger?

[Joe1]

Will a John Dere 770with about 20 - 21 PTO HP be able to handle an 18" auger, particularly in heavy clay soil? I have not used an auger with this tractor before and do not want to break anything on the tractor.

Seriously, thank you in advance to all your hands on experts.

 

[Menagerie-Manor]

If you research 3 point Auger sizes and capabilities they generally include HP requirements, 18" is gonna be pushing the envelope.

 

[rScotty]

Will a John Dere 770with about 20 - 21 PTO HP be able to handle an 18" auger, particularly in heavy clay soil? I have not used an auger with this tractor before and do not want to break anything on the tractor.

Seriously, thank you in advance to all your hands on experts.

Why an 18" hole?

The hp required for a post hole drill varies a lot on the way the auger is built. Soil is so completely different everywhere that all a person can do is relate their own experience.
In clay, a lot depends on moisture and advancing the depth very slowly....sometimes with water.

Unfortunately, an inexpensive auger with large pitch, a simple screw tip, and a single cutting edge won't do much in heavy clay soil regardless of auger size. And an 18" would require a really big heavy tractor and probably in heavy clay a category II 3pt. And even so, that's not the way I'd go.

If you use an better auger with a fine pitch and dual cutting edges with bolt-on carbide teeth - a fairly expensive auger - then your 770 should be able to handle a 9 to 10 inch size in heavy clay if everything is right and you can advance it slow enough....maybe with some water. Not sure about an 18" on a little tractor in any soil. That's pushing things.....

Give it a try and let us know.

rScotty

 

[Tinhack]

An 18" auger in heavy clay soil will most likely require 80-120 Hp. If you're digging footers, I'd just farm it out to someone with the equipment. They usually have a large truck like a drilling rig.

 

[rScotty]

An 18" auger in heavy clay soil will most likely require 80-120 Hp. If you're digging footers, I'd just farm it out to someone with the equipment. They usually have a large truck like a drilling rig.

I agree. You said the same thing as i did, but much more economically.
BTW, we hired a drill rig to do holes for our pole barn. Best decision we could have made.
They not only punched the holes in the right place, they set the poles.

 

[M59]

Will a John Dere 770with about 20 - 21 PTO HP be able to handle an 18" auger, particularly in heavy clay soil? I have not used an auger with this tractor before and do not want to break anything on the tractor.

Seriously, thank you in advance to all your hands on experts.

Joe1,
First impression. a big NO.
What your not stating is type of auger. Hydraulic or 3 pt?
Second impression. There is no way at 21 pto hp that your going to move clay on a 18 inch dia hole regardless of auger drive type.

My auger preference is hydraulic mounted on FEL via SSQA so you can easily see what you are doing and can apply massive amounts of down pressure and reversing auger when it binds up or needs flutes cleared. Wet clay cuts easier but is very gummy and clogs flutes quickly so auger either needs to come up out of hole frequently OR you need lots of hp to hydraulically deliver the needed torque and dry clay is like drilling cement.

My 2 cents running a SSQA hydraulic auger on 59 hp M59 TLB and augers up to shrub prep auger of 30 inch dia.

 

[Rockbadchild]

I have solid clay soil and made many holes, I don't see why you couldn't, I dig my holes at a very low RPM to me HP is not a factor and I don't see why it would be. If its wet you need to lift it every so often if not the bit get suck there then you are in a pickle, you need to disconnect the PTO shaft and get a pipe wrench and turn it the opposite direction or hand shovel it out. If its dry it is very slow and I needed to apply weight to it for it to go down, the clay came out in small chips just chewing at it. More HP doesn't apply more weight, the only thing Hp will do is make your tractor heavier so yo have more lift capacity to lift the auger full of dirt ... lots of folk do their holes with a two man auger not many HP there, it’s a nasty job but people do it.

To me the worse thing that can happen is you will stall the tractor but just go slow.

 

[old and tired]

....if not the bit get suck there then you are in a pickle, you need to disconnect the PTO shaft and get a pipe wrench and turn it the opposite direction....

I did this, you don't have to unhook the PTO shaft. Turn off the tractor, I had bought a 36" pipe wrench (just in case this happened) and unscrewed the bit.

Go slow is key, and have your foot on the clutch to be press quickly!!!

 

[Bavarian]

Pto auger don't need much HP.
As mentioned, weight or down pressure might be the deciding factors next to unexpected obstacles like rocks in the ground.

 

[akadave]

I'm going with nope.