tooth grind angle on post hole auger

claya1

Member

Equipment
Kubota
Sep 24, 2021
38
6
8
sacramento
I am re-grinding the welded-on teeth on a post-hole auger. Should the teeth have a high positive rake (very sharp like 45°), or very low (more blunt like 10°).
 

85Hokie

Moderator
Staff member
Lifetime Member

Equipment
BX-25D ,PTB. Under Armor, '90&'92-B7100HST's, '06 BX1850 FEL
Jul 13, 2013
10,269
2,104
113
Bedford - VA
I am re-grinding the welded-on teeth on a post-hole auger. Should the teeth have a high positive rake (very sharp like 45°), or very low (more blunt like 10°).

The first will bite much better......... which may NOT be what you really want. If it bites hard and gets stuck.... you will be stuck! A less aggressive angle will scrape away soil, breaking it up to spiral up better.

I would stick with the OEM angle unless soils are really different.
 

claya1

Member

Equipment
Kubota
Sep 24, 2021
38
6
8
sacramento
The first will bite much better......... which may NOT be what you really want. If it bites hard and gets stuck.... you will be stuck! A less aggressive angle will scrape away soil, breaking it up to spiral up better.

I would stick with the OEM angle unless soils are really different.
What is a typical OEM angle, 45°? I think it is the back rake angle that really matters. Because the teeth are so worn down on this one, the bottom of the teeth just surf on the dirt.
 
Last edited:

ddavis83864

Active member

Equipment
Kubota Grand L6060
Mar 3, 2021
120
140
43
83801
Keep in mind that if you are below the equator that the angle has to be the reverse. :)

Good luck, hope it all works out well for you.
 

claya1

Member

Equipment
Kubota
Sep 24, 2021
38
6
8
sacramento
Factory angle is usually 45 degrees.
Built the auger teeth back up with welds. (Picture is pre-repair). But the tip is so severly worn, it will not bite into the dirt. Screw-on tip will not unscrew.

Suggestions on how to remove the tip? I have a gas torch & an induction welder. Gas torch will just transfer heat to the tip eventually. TSC has a Countrywide replacement tip, but are the threads on these a standard form? I do not want to waste half a day removing the tip, just to find the threads are not compatible.

Induction heated as close to the threads as possible to 1000°F. That tip is not budging at all. Suggestions?
 

Attachments

Last edited:

Henro

Well-known member

Equipment
B2910, BX2200, KX41-2V mini Ex.
May 24, 2019
5,116
2,341
113
North of Pittsburgh PA
Built the auger teeth back up with welds. (Picture is pre-repair). But the tip is so severly worn, it will not bite into the dirt. Screw-on tip will not unscrew.

Suggestions on how to remove the tip? I have a gas torch & an induction welder. Gas torch will just transfer heat to the tip eventually. TSC has a Countrywide replacement tip, but are the threads on these a standard form? I do not want to waste half a day removing the tip, just to find the threads are not compatible.

Induction heated as close to the threads as possible to 1000°F. That tip is not budging at all. Suggestions?
I assume when you said induction welder you meant induction heater?

If you can weld, you might consider just cutting the old tip off and welding the new one on in its place...

Or maybe you could use a cutting disk in a four inch grinder and slit the old tip up one side to loosen it a bit that way?
 

Captain13

Active member

Equipment
M7040 4WD ROPS, ZD28, Woods (84” box blade, 72” harrow, 48” pallet forks)
Feb 27, 2019
516
168
43
Kathleen, GA
Henro’s suggestion is a good one. Also, you could try the method used for removing pressed on axle bearings. Use a grinder as suggested by Henro or a die grinder with a cutting disc. Cut a groove in the tip, but not deep enough to damage the internal threads. Then take a chisel, put the sharp end in the grove and hit it with a hammer. That will usually pop the steel open and release it. I do that with bearings and it works great with no damage to the axle when I use that method.

Of course, if the new tip screws into instead onto existing threads this won’t work.
 
Last edited:

claya1

Member

Equipment
Kubota
Sep 24, 2021
38
6
8
sacramento
I assume when you said induction welder you meant induction heater?

If you can weld, you might consider just cutting the old tip off and welding the new one on in its place...

Or maybe you could use a cutting disk in a four inch grinder and slit the old tip up one side to loosen it a bit that way?
Was able to grind & relief cut the tip enough to loosen it, and unscrew. Fortunately the TSC Countrywide tip threads matched the old tip.
 

GeoHorn

Well-known member
Lifetime Member

Equipment
M4700DT, LA1002FEL, Ferguson5-8B Compactor-Roller, 10KDumpTrailer, RTV-X900
May 18, 2018
5,570
2,938
113
Texas
The first will bite much better......... which may NOT be what you really want. If it bites hard and gets stuck.... you will be stuck! A less aggressive angle will scrape away soil, breaking it up to spiral up better.

I would stick with the OEM angle unless soils are really different.
…different from …what..?
 

GeoHorn

Well-known member
Lifetime Member

Equipment
M4700DT, LA1002FEL, Ferguson5-8B Compactor-Roller, 10KDumpTrailer, RTV-X900
May 18, 2018
5,570
2,938
113
Texas
Was able to grind & relief cut the tip enough to loosen it, and unscrew. Fortunately the TSC Countrywide tip threads matched the old tip.
What brand/model is the auger…??