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THUNDERBAY 12 Inch Diameter 36 Inch Long Earth Auger Bit with Fishtail Point and Patent Shock Spring

  • Based on 90 reviews
Condition: New
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Availability: In Stock.
Fulfilled by THUNDERBAY PRODUCTS

Arrives Wednesday, Feb 11
Order within 7 hours and 36 minutes
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Size: 12" Diameter


Features

  • Replaceable fishtail point #8958HDJ threads in in seconds
  • Hardened, abrasion resistant, replaceable cutting blade
  • 36 inch overall length for maximum drilling depth
  • Drill even deeper with optional extenions
  • Fits all ThunderBay, Earthquake, Dolmar, Echo, and Maruyama one AND two man earth auger powerheads

Material: Cobalt Steel


Cutting Diameter: 304.8 Millimeters


Finish Type: Uncoated


Shank Type: Straight


Brand: THUNDERBAY


Is Discontinued By Manufacturer ‏ : ‎ No


Package Dimensions ‏ : ‎ 40 x 12 x 11.8 inches; 1 Pounds


Item model number ‏ : ‎ c4d7ccb9-e7a9-4f32-b1f6-5d8927e643e9


Date First Available ‏ : ‎ February 7, 2016


Manufacturer ‏ : ‎ ThunderBay Outdoor Products


Best Sellers Rank: #299,964 in Patio, Lawn & Garden (See Top 100 in Patio, Lawn & Garden) #161 in Augers & Posthole Diggers


#161 in Augers & Posthole Diggers:


Customer Reviews: 4.3 4.3 out of 5 stars (95)


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Wednesday, Feb 11

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

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View our full returns policy here.

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Top Amazon Reviews


  • Dig it man!
Size: 12" Diameter
Was the right tool for the job! Punched out 4- 48" deep holes in a couple hours by myself! Wasn't easy as there was blood, sweat, tears and a muffler brand on my chest but was a dam site better than the manual way! Would recommend and hope I never have to use it again!!
Reviewed in the United States on August 22, 2024 by Dave McC

  • Can't go wrong.
Size: 12" Diameter
I'm contractor from Illinois. 95% of my business is building decks on new walkout style homes. I've had this auger for a little more then a year and it is fantastic. It cuts through the ground as fast as anyone could possibly want. Most of the time I have to lift up slightly while drilling to keep the auger from diving to quick. A pretty good problem to have in my opinion. Can not say enough about the quality of the product ... show more
Reviewed in the United States on August 3, 2017 by Brenden Taylor

  • Fit my earthquake
Size: 12" Diameter
Good price and fast shipping
Reviewed in the United States on October 26, 2024 by Greg Tabor

  • Great Durable Auger
Size: 14" Diameter
Bought this auger to use with my Earthquake Model# 9800K 2-Person Kohler Powerhead. Both the powerhead and this auger are beasts. However you need to keep some spare grade 8 bolts on hand for the auger because the original bolts bend easily and will shear off after a few hours of use.
Reviewed in the United States on July 31, 2019 by The Honest Critique

  • 12” bit takes all of 85cc to spin in clay soil. Inspect auger before using to avoid disappointment.
Size: 12" Diameter
Welds on the unscrew-able fishtail point are questionable as there are several holes due to impurities. After trying for over an hour to get this bit to dig I discovered that the cutting edge had been bolted on with the bevel facing up from the factory vs down as it should have been. Had I not had my 8” version to compare it to I would have returned it immediately! After turning the cutting edge and bolting it on with the threads down, I was able to get it to work. I used this bit on an 85cc powerhead and would not recommend anything less if you intend to use it in clay soil. Other than the sloppy welding and backwards assembly it is quite stout. ... show more
Reviewed in the United States on October 7, 2025 by Glenda Anderson Glenda Anderson

  • Screw Snapped During Use
Size: 12" Diameter
Had an awful time using this, one of the spring screws snapped on me. My yard is clay soil, perhaps this would have worked better in softer dirt. The smaller auger attachment that came with my earth auger performed so much better.
Reviewed in the United States on July 27, 2025 by James Ballon

  • Does not like tree roots
Size: 12" Diameter
Works great in soil, emphasize, soil not clay. But in dirt it is really good, it’s a little big for my one man auger machine, but I use a smaller one first then the 12” and it works great when you don’t have roots, I live in the woods.
Reviewed in the United States on September 4, 2023 by Charles Burgett

  • Nice
Size: 12" Diameter
It was great
Reviewed in the United States on July 18, 2025 by Jeffrey Vanderpool

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