post hole digger blades

[musselmark]

I posted this in "attachments" but got no response so I will try here.

I bought a used 20 year old john deere pto post hole digger with 14" auger, I went to john deere to get replacement blades and they wanted $100.00 for 2 little blades. I am going to make my own, would leaf spring steel be a good choice? How about an old road grader blade?

 

[brown40]

Any picture of the set-up? TSC sells them for waaay less, Agri-supply too, unless JD has a 'proprietary blade design' (that wouldn't surprise me), you could likely modify the leading edge to accept regular ones with about the same time/effort, then you'd be set to bolt-on going forward. They are a 'soft item' and not meant to last, so what grade of steel you'd use would be whatever suited you. Harder would last longer.

 

[musselmark]

I checked with many of those suppliers such as TSC, they have 12" but mine is 14", must be a rare size. One other thought I had was making them from 3" X 5/16" mild steel flat bar and hardfacing the cutting edge, that would the easiest for me.

 

[brown40]

Mine has a replaceable screw tip, then two bolt-on teeth that are at each outside edge--only covers three inches or so on each side of the 12" diameter. Cheap Countyline one. What's the end of yours look like?

 

[CDennyRun]

Leaf spring would definitely work, but I think you would have to be very selective as to what wire/stick you choose. I've never welded spring steel. I've welded tool steel with mild steel wire, and it didn't work out so well! You could call up your local welding supplier and find out though. Of course this is all if they're welded, and not bolt on replacements.

 

[musselmark]

there is no welding, other than maybe putting a bead of hardfacing rod on it. my old blades are basically the same dimensions as a 3" wide leaf spring cut to length. i have to drill 2 holes but could do that with my plasma cutter or OA torch

 

[CDennyRun]

I see. if you hard face spring steel with mild steel wire, you might actually make it weaker. I don't think you would need to hard face it though. spring steel is incredibly hard!

 

[musselmark]

OK, but there are special hardfacing stick welding rods made just for this reason. maybe they are no harder than spring steel, i don't know. Wearshield Hardfacing Stick Electrode | Lincoln Electric Canada

 

[musselmark]

OK, but there are special hardfacing stick welding rods made just for this reason. maybe they are no harder than spring steel, i don't know. Wearshield Hardfacing Stick Electrode | Lincoln Electric Canada

 

[BukitCase]

Another possible option - you already have a plasma cutter, so if there are any scrap places in your area (or decent NEW steel suppliers) it might be easier/better to ask about AR plate - typically called AR400 or AR500 - I put some of that on my hoe bucket for wear strips several years ago.

Started out ordering 4 strips of 1/4" thick, 3" wide x 3 feet long - they were cut for me, but there was just enough dross on the edges to make them NOT friendly to be near without gloves on, so I took my 9" grinder with a new disk and just broke the edges enough to remove the danger of getting cut.

That "small" bit of grinding took about 30 minutes per edge (3 feet) Did I mention this stuff is HARD?

If you can find some, cutting it with plasma (holes AND beveled edge) would likely last longer than your auger. I wouldn't recommend an O/A torch for this, plasma is several times as hot and will cut fast enough NOT to take the "goodies" out of the steel as much as a torch.

IME, hardfacing is best left to LARGER surfaces - I have some Stoody HF rod and used it to make a couple passes inside the ripper slots on my Gannon box scraper. Small, short passes are NOT fun, if I have to do that again I'll probably pay for a small spool of hard facing WIRE.

Not to mention - if it's hard enough to last, WHAT are you gonna SHARPEN it with??

Just some suggestions from an old fart who's had 70 years to figger out what DOESN't work - my advise is free, and worth every penny ...Steve