Post Hole Auger Parts

The rock itself is not particularly hard as I can put some moderate weight on the auger and grind through. Unfortunately the wear on the auger knives is tremendous and I've only gotten 5 or 6 holes before the knives are ground away.

The auger has a replaceable spiral point, and while this gets quite hot, so far its holding up. The knives however appear to be cast metal and can't take the punishment.

My first question is, what do professionals do when having to auger down into "sandy" rock?

Are there replacement knives that are made of harder material (i.e. hardened steel) that might hold up better?

The auger diameter is 6 inches with one knife on each auger edge (2 knives total).

Suggestions?

John

The posts I'm burying at the moment are corner posts and gate posts so I'd really like to get them down 3 feet. I've got some smaller posts around the property buried at 2 feet, but the soil is such that they didn't anchor well.

I may end up having to concrete some of the posts.

I've been doing a bit more research since my original post. The original auger manufacturer does have some hardened knives and is sending me a pair. If I can get 15 or 20 posts with a set of hardened knives, and if they are not too expensive it might work out okay.

There also are augers that are specifically made for digging into rock. I found one of these for around $400. Thats a little on the high side for my budget, but still cheaper than having to pay someone to come in a drill the holes for me. I've estimated something like 180 holes for the upper pasture.

Thanks for the reply,
John

You make an excellent point. I weigh about 220 and standing on the 3 point hitch arm does not make much difference. When I need down force I like to borrow my neighbors John Deere compact tractor which has a front mounted bucket. I simply center the bucket over the post hole digger frame and lower the bucket enough to just raise the front wheels on the little John Deere. It appears that if the auger is going to drill the hole it will do so with that much weight. I doubt that adding more weight than that would be either productive or sensable.

My tractor that drives the post hole digger is an old John Deere model 50. One of the old two cylinder models. It has all sorts of torque at low engine speeds, which makes it ideal for spinning the auger slowly.

Regards,
John

The link below shows the carbide point and some other specialized blades. These are for the Little Beaver brand, but might work for your application.

• Little Beaver augers

Thanks for the link. I noticed that the carbide points actually mount in the middle of the auger and extend to the full diameter of the auger. This makes sense when drilling the really hard stuff.

I think I can adapt this to my auger. I've got an old center point that I can make into an adapter that should fit one of their carbide tips.

The auger is made by Dale Phillips Co. I'll probably give them a call to see what they recommend.

Unfortunately there is lots of big rock in this field, but as long as I can keep good knives and tips on the auger, my old John Deere model 50 tractor has enough torque to spin the bit slowly and not blink an eye.

Thanks again,
John

Thanks for the suggestion,
John

Thanks for the post. The flighting on this auger is pretty good and appears to be able to take the added weight I put on it. The tip and knives appear to be cast, possibly forged. I don't know enough about metalurigy to know if I can harden the cast knives but its an idea. The alternative is to replace the knives every 5 or 6 holes. I estimate something like 180 holes to drill in this field and while I COULD buy 30 sets of knives I'd rather not.

Regards,
John