6 Best Self Feeding Auger Bits For Fence Posts Old Farmers Swear By
Explore 6 farmer-approved self-feeding auger bits. These time-tested tools pull through tough wood for fast, clean fence post holes with less effort.
You’re staring at a 100-yard fenceline, a stack of posts, and a post-hole digger that feels heavier than it did last year. You know the work ahead is back-breaking, but it doesn’t have to be. The right self-feeding auger bit, chucked into a powerful drill, can turn a weekend of agony into an afternoon of satisfying work.
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The Right Auger Bit: A Fencing Game-Changer
A good auger bit is more than just a drill accessory; it’s a force multiplier. It transforms the brutal, repetitive motion of a manual post-hole digger into a controlled, efficient process. Instead of fighting the ground with every scoop, you’re guiding a tool that pulls itself into the earth.
The real magic is in the "self-feeding" screw tip. This small, threaded point bites into the soil and pulls the rest of the bit downward, doing most of the hard work for you. All you have to do is keep the drill steady and manage the torque. This means less fatigue, straighter holes, and a much faster pace.
Don’t mistake this for an easy button, though. Hitting a big rock or a thick root can still jolt your wrists, which is why a drill with a clutch or a side handle is non-negotiable. But compared to the sheer physical toll of a clamshell digger, a quality auger bit feels like a modern miracle. It makes the difference between dreading a fencing project and actually looking forward to it.
Irwin Ship Auger: The All-Around Workhorse
When you just need a bit that works without any fuss, the Irwin Ship Auger is the one you grab. It’s not the fanciest or the most aggressive, but it is incredibly reliable. Its classic design has been proven over decades for a reason: it balances cutting efficiency with durability.
The Irwin excels in typical farm soil—loam, sandy soil, and even moderately compacted ground. The single-spur cutting edge and wide flutes do a respectable job of clearing material out of the hole, preventing it from getting bogged down too easily. It’s the kind of tool you can throw in the truck and trust to handle 90% of the jobs you encounter.
This isn’t the bit you want for drilling through solid clay or a maze of tree roots. It will struggle, and you’ll end up fighting the drill more than the ground. But for general-purpose fencing, repairs, and setting posts in decent soil, the Irwin is a dependable standard that won’t let you down.
Wood Owl Tri-Cut: For Cleaner, Faster Holes
The Wood Owl Tri-Cut is a different beast entirely. Its claim to fame is a unique head with three cutting edges instead of the usual one or two. This design allows it to shave material away with remarkable speed and precision, leaving behind a surprisingly clean hole.
In softer soils or when you need to drill through an existing wood fence brace, the Tri-Cut is unbelievably fast. It pulls itself through the material with very little downward pressure required. If your ground is mostly topsoil and free of major obstructions, this bit will let you set posts at a blistering pace.
However, that precision comes with a tradeoff. The finely honed cutting edges are more susceptible to damage from rocks and heavy gravel. Think of it as a racehorse, not a plow horse. If you know your soil is rocky, you’re better off with a more robust design. But for clean, fast work in forgiving ground, the Wood Owl is in a class of its own.
Diablo Ship Auger: Power Through Tough Ground
When the ground fights back, you need a bit that fights harder. The Diablo Ship Auger is built for exactly that. It’s an aggressive, heavy-duty tool designed to chew through the kind of compacted, root-infested, and rocky soil that makes other bits grind to a halt.
The secret is in its hardened cutting edge and aggressive feed screw. This combination creates a powerful pulling action that relentlessly bores into tough ground. The deep flutes are also optimized for pulling out large amounts of debris, which is crucial when you’re wrestling with clay and embedded stones.
This is not a delicate instrument. Using a Diablo bit requires a powerful, high-torque drill and a firm grip. It will grab and pull with authority, so be ready for it. If your property is full of challenging soil conditions, the Diablo is your best bet for getting the job done without burning out your drill or your arms.
Bosch Daredevil: Aggressive and Long-Lasting
The Bosch Daredevil lives up to its name. It’s designed for aggressive performance and built to last, combining speed with impressive durability. The reinforced spine and hardened cutting surfaces mean it can take a beating from rocks and debris without getting dull or deformed.
What sets the Daredevil apart is its double-cutter and reamer edge design. This helps it create a cleaner hole than many other aggressive bits while still powering through tough material. The cone-threaded tip pulls with exceptional force, making it feel like the drill is doing all the work, even in dense wood or compacted soil.
This is a premium bit, and it performs like one. It’s an excellent choice for someone who does a lot of fencing and needs a tool that can handle a wide variety of conditions day in and day out. It offers a fantastic blend of the Diablo’s raw power and the Wood Owl’s speed, making it a top-tier choice for serious work.
Lberg Hex Shank Auger: Top Value for the Price
You don’t always need the most expensive tool in the shed to get the job done. The Lberg Hex Shank Auger is a prime example of a value-oriented tool that punches well above its weight. It offers solid performance for a fraction of the price of the big-name brands.
The most important feature here is the hex shank. This provides a secure, non-slip grip in your drill’s chuck, which is absolutely critical when you’re dealing with the high torque of drilling into the earth. The bit itself is a straightforward, no-frills design that works surprisingly well in most soil types that aren’t solid rock or clay.
Will it last as long as a Bosch or a Diablo? Probably not. The steel may not hold its edge quite as long after repeated encounters with gravel. But for occasional projects or for someone just starting out, the Lberg provides incredible utility for the money. It’s a smart, practical choice that gets posts in the ground without breaking the bank.
Power Planter Auger: Built for Clay and Roots
Plant faster and easier with the K-Brands Auger Drill Bit Set. This set includes 1.6" and 3.5" diameter bits, both 16" long, that attach to any standard 3/8" hex drill to quickly dig holes for bulbs, plants, fence posts, and more.
Sometimes the best tool for the job comes from an unexpected place. The Power Planter auger is marketed for gardeners, but its rugged, all-steel construction makes it an absolute monster for digging post holes in the worst possible conditions, especially heavy clay and root-filled ground.
Unlike ship augers that shave material, the Power Planter is designed to dig and excavate. Its spiral design acts like a screw, pulling dirt, clay, and chopped-up roots straight up and out of the hole. This is a game-changer in sticky clay that would pack the flutes of a traditional ship auger solid.
Because it’s not a self-feeding design with a screw tip, you have to apply some downward pressure. But its ability to clear the hole is second to none. If you’ve ever fought with heavy, wet soil that refuses to come out of the hole, the Power Planter is the solution you’ve been looking for. It’s a specialized tool, but in the right situation, it’s unbeatable.
What to Look for in a Fence Post Auger Bit
Choosing the right bit comes down to matching the tool to your drill and your dirt. A bit that’s perfect for your neighbor’s sandy loam might be useless in your rocky clay. Keep these key factors in mind.
- Shank Type: Always choose a hex shank if you can. The flat sides prevent the bit from slipping in the drill chuck under high torque. A standard round shank is far more likely to slip, which can damage both the bit and your drill.
- Tip Design: A self-feeding screw tip is essential for most applications. It pulls the bit into the ground, saving you immense physical effort. The more aggressive the thread, the faster it will pull.
- Material and Durability: Look for bits made from hardened or high-carbon steel. A durable cutting edge is crucial for maintaining performance after hitting the inevitable rocks and roots hiding in the soil.
- Length and Diameter: The bit’s length should be at least 6-8 inches longer than your desired hole depth to allow for easy clearing of dirt. The diameter should be 1-2 inches wider than your post’s diameter to leave room for concrete or for tamping dirt back in. For a standard 4×4 post (which is actually 3.5" x 3.5"), a 6-inch auger is a perfect size.
Ultimately, the best strategy is to know your land. If you have varied soil, it might be worth owning two different types of bits—a fast one for the good areas and a powerful one for the tough spots. The right tool makes all the difference.
In the end, the brand name on the bit matters less than how well it suits your specific piece of land. A smart choice saves your back, your time, and your patience, letting you build a fence that will stand strong for years to come. That’s a trade worth making every time.
