Selecting the proper earth drill and accessories for any hole digging project

Installing a fence, planting shrubs, putting in new landscape lighting – different grounds care projects with one common link: each requires the proper hole to be dug in order to complete the task properly. How hard is it to dig a suitable hole? While the process is far from rocket science, it’s not quite as simple as one would expect either. All hole digging projects may appear to be the same on the surface, but it’s often what’s below the surface that really matters. Additionally, the available equipment and accessory options, while great for enhancing productivity, can make things a bit more complicated for the operator.

Many models of hydraulic drills incorporate a forward and reverse lever for easier, safer operation in virtually any soil condition.

These days, it’s more than just grabbing a shovel or hand-held posthole diggers and hitting the dirt; sophisticated, productive earth drilling equipment exists. Even though they all achieve the same basic end result, a hole, all one-man earth drills are not the same. No longer “just a hole digger,” designs and features have advanced and improved over the years; the industry has come a long way from the simple hand method of digging. With many models and accessories available, units are now able to match specific applications and cut through virtually any type of ground. Whether the project calls for several identical holes in typical lawn soil, or a single large hole in rocky soil, there is a model and appropriate accessories available to achieve the best results safely and efficiently.

Because each machine will perform better in certain situations, and offer features and options to further enhance the process, it’s important to consider the entire scope of the digging project when selecting a drill. All aspects, from the soil structure and project location to the hole depth, diameter and frequency will come into play. Despite differences in projects, the bottom line remains the same. Choosing the proper drill will complete the job quickly and effectively, and even help to dig up some ROI along the way.

Style is an option

Engine-powered, one-man earth drills are typically available in two common styles: hydraulic and mechanical. While often similar in appearance in their most basic configurations, these two styles operate differently and are built with distinct features and options to make them better suited for certain projects.

Offering slower, precise speed and the ability to utilize larger-diameter augers, a hydraulic earth drill is ideal for wider-diameter holes.

Hydraulic drills are designed for the most challenging digging projects, including those in more complex soil conditions and even frozen ground. Hydraulically powered units offer controlled, precise operation at a lower speed and higher torque, allowing them to drill accurately in even the most difficult applications. Additionally, hydraulic models are ideally suited for rougher terrain and rocky conditions, as they incorporate a reverse auger operation function. Should the auger become lodged under an object, such as a rock or tree root, it can be removed safely and easily by running the auger in reverse.

Generally accepting of larger-diameter augers, these units are ideal for single-hole projects such as mailbox installation. Most hydraulic drills are also compatible with smaller augers, opening them up to a variety of other lawn and landscape projects.

Though versatile, hydraulic drills do pose one distinct drawback: speed. Because they offer controlled operation at a higher torque, the trade-off with hydraulic units is slower operation. Projects requiring multiple holes wouldn’t be the ideal setting for a hydraulic unit to shine, as efficiency would not be maximized. For those types of projects, a better choice exists.

Compact, lightweight and still packing a powerful punch, mechanical drills are transmission-powered units that offer high-speed rotation for productivity and clean holes. These drills are best suited for use with smaller-diameter augers and, due to their high speed, are ideal for projects calling for several, narrow holes, such as in fence and deck installations, as well as decorative plantings.

Unlike hydraulic models, mechanical units aren’t equipped with a reverse feature. The lack of reverse operation can present a problem if the auger were to become caught under an obstruction, making it necessary for the operator to remove the auger manually, using a pipe wrench in a counterclockwise motion.

Ultimately, the drilling task is the best indicator of which drill is best suited for the project. It will also dictate the required auger size. Based on the project specification for hole diameter, the right size auger can easily be paired with the selected drill, and most manufacturers will offer several options, from the smallest model used for applications like soil nursery work, up to the largest augers commonly used in tree planting.

The next factor that will affect the selection process requires a bit of digging to get the info – literally. Just as important as why a hole is being drilled is the type of soil being dug. As mentioned, mechanical drills are best suited for loam-type soil conditions, while hydraulic units are better in tougher, rocky soils or even frozen ground. The decision doesn’t end there; the appropriate auger model, point and blade must be properly selected to handle the soil conditions.

Below the surface

The auger’s point and blade (commonly referred to as its tip) does the actual cutting as the unit rotates, and helps to protect the auger’s flighting from excessive wear. As important as the tip is to drilling success, it’s imperative to know the available options and in what soil each will perform best.

A standard, general-purpose point with a side-mount cutting blade will work well in most conditions, but is particularly suited for sandy, loam-type soils and softer clays. These general-purpose tips will be compatible with most standard augers and come in varying lengths and diameters.

When drilling in more solid, dense material such as limestone, sandstone, hard clay and frozen ground, a carbide blade will offer the best performance. Rather than digging into the material, a carbide blade will cut the clay or ground into small pieces, allowing the operator to drill much faster. This blade mounts to the bottom of most standard augers and will replace both a general-purpose point and cutting blade.

If the drilling task includes loose, gravely soil or rocky conditions, a heavy-duty auger, point and blade combination will tackle it best. Most effective when attached to lower speed drills like hydraulic units, a heavy-duty auger is recommended for challenging soil conditions. It features a larger, more rugged and aggressive flighting than standard augers, and also incorporates a special dirt-tooth blade in addition to a heavy-duty point.

Jobsite conditions, particularly soil, play an important role in proper unit selection. The location may present additional challenges, most notably, transporting the auger to the desired work area. The good news is both mechanical and hydraulic augers aren’t just designed for easy operation by one person – they’re intended for simple, one-man transport as well. While the most basic designs are compact and easy to move, some manufacturers offer a variety of design options for various methods of transport.

Oh, the places you’ll go

When choosing an earth drill, mobility needs must be assessed. Most models are designed for easy transport, some incorporate front and rear handles for convenient loading and unloading. Mechanical units are generally the easiest to move, with the ability to be loaded in a car trunk, the back of an SUV or in the bed of a pickup. Because they are typically a bit larger, hydraulic units are less convenient to move from site to site. On the flip side, they offer a variety of transport modes, allowing operators flexibility to match their vehicle and space needs.

The smallest hydraulic models are best moved with a pickup or small trailer. In cases where truck and trailer space is minimal, consider a model designed to be towed behind the vehicle, as it frees up room for jobsite tools and other equipment. For those looking for yet another alternative, a new style has recently emerged that takes portability options even further.

A hydraulic unit is now being offered that separates into two pieces, making the entire unit lighter and more manageable. The power pack can be placed in the vehicle, while the rest of the drill is transported behind the vehicle and off the ground, eliminating common towing hassles. A special hitch design, compatible with even small SUVs and pickups, allows it to sit up and off the ground.

A drill that is easy to move from point A to point B provides greater efficiency and saves time and energy, but once the unit is on-site, safety becomes a top priority and must be taken into consideration.

Play it safe

It’s widely understood that digging into the ground can be extremely dangerous. One-call phone numbers have been established for every area across the country to help protect operators and let them know what’s below the surface before digging. (You can dial 811 and be connected to the one-call center for your area to find out what’s underground in the area you plan to dig.) However, the drill itself can pose a safety threat to the operator, making it imperative to look for units designed with added safety features.

Certain models incorporate the engine and auger into one piece, while some manufacturers offer a configuration that places the engine on a wheeled chassis, which sits back a few feet from the operation point. Compared to models that mount the engine on the operator’s handle, a separate mounting keeps exhaust emissions at a distance. Even in well-ventilated areas, carbon monoxide poisoning is serious, and minimizing its likelihood of occurring in any way will increase operator safety. This style may also protect the operator in additional ways.

Some models with a separate engine chassis utilize a steel torque tube that protects operators from potential harm by transferring digging torque from the drill head to the engine carriage. This allows operators to use larger-diameter augers without fear of kickback. Additionally, the torque tube enhances drilling ease and reduces operator fatigue, effectively improving overall drilling safety. A less-fatigued operator will be more likely to pay attention and handle the drill properly. As an added benefit, easier operation will reduce physical stress on the operator, including back problems and muscle strains.

A pressure relief valve is another safety feature to look for, and one that is often incorporated on hydraulic units. If the auger becomes overworked and the drill reaches a certain hydraulic pressure, the valve will release, stopping the auger’s rotation. This halts the drill before it reaches a point where it stops the engine or causes damage to the machine.

Mechanical units also come with unique safety features, one in particular is a centrifugal clutch. If a buried object is encountered or the auger is overloaded, the clutch automatically slips, protecting the operator from serious injury. Additionally, this eliminates potential damage to the drive cable and transmission gears, reducing the likelihood of repairs or full replacement.

When the crucial considerations have been identified, and the drill choice and accessories have been narrowed down, the final decision rests in the details. From ergonomic designs and the unit’s engine, to reduced maintenance and enhanced portability, these extra features play a role in finding a productive solution that will maximize overall drilling efficiency and safety.

Extra, extra

Whether an experienced operator or first-time hole digger, all ultimately desire a machine that’s easy to use. An ergonomically designed piece of equipment will provide a more comfortable, user-friendly experience, further enhancing operation ease.

A unit with large, easy-to-grip handles will allow for better control and more comfortable operation. Additionally, look for a model that places operator controls on, or in close proximity to, the handle. Certain functions, such as a hydraulic unit’s forward/reverse switch should be adjacent to the machine’s on/off switch for added convenience.

Choosing a unit with a high-quality engine is a must, as a drill’s operation is greatly dependent on its engine. Look for one from a reputable manufacturer that includes a warranty and adequate service network. For portable units offering the engine on a separate chassis, one that includes a steel frame will help protect the engine and its components.

To ensure the machine is safe for even the most delicate lawns and turfs, consider a unit with large, pneumatic or semi-pneumatic tires. The benefit will be two-fold, as quality tires won’t damage turf, and will also allow the unit to easily traverse a variety of terrain conditions.

Beyond providing multiple auger tips, look for a manufacturer that offers augers in multiple lengths and diameters. Some manufacturers offer snap-on augers, making the change-out process quick and easy and eliminating the need for extra tools. Snap-on auger extensions offer the ability to achieve various digging depths without requiring multiple augers, adding versatility and saving money.

Finally, just like any piece of equipment, an earth drill that’s easy to care for is ideal. In the event the machine becomes damaged, a unit that can be serviced in the field, and doesn’t require special tools to do so, will be most convenient. As an added bonus, a drill that’s easy to maintain will encourage the operator to stick to a routine maintenance schedule, preventing future issues, enhancing longevity and, ultimately, maximizing the drill’s ROI potential.

Thanks to advancements in drill designs, as well as the available features and accessories, what was once a simple hole digger is now much more – it’s a complete solution to any digging project, simple or complex. Taking the time to learn about the available options prior to selection will ensure the success of a project on all levels, from safety and productivity to quality and equipment ROI.

The author is sales manager for Little Beaver, Inc. With more than 30 years of experience, he is an expert on hole digging equipment.