If you work the land or maintain a rural property, you'll come across plenty of technical terms when choosing tractor implements and attachments. This glossary covers the key terminology you need to know when selecting, matching, and operating implements for compact through to large tractors. It's written for farmers, lifestyle block owners, and anyone shopping for quality gear to get the job done right.
540 RPM PTO
The standard PTO shaft speed used on most compact and utility tractors. When an implement is rated for 540 RPM, it means the PTO stub on your tractor needs to spin at that speed for the implement to operate correctly. Most flail mowers, rotary hoes, and post hole borers in the compact-to-mid-range bracket are designed for 540 RPM.
Auger Bit
The interchangeable spiral drill attachment that fits onto a post hole borer's gearbox output shaft. Auger bits come in a range of diameters to suit different post size. Choosing the right bit diameter and style is one of the most important decisions when setting up a post hole borer for fencing work.
Compact Tractor
A tractor class typically rated between 25 and 60 HP, popular on lifestyle blocks and smaller farms. Compact tractors generally use Category 1 three-point linkage and a 540 RPM PTO. They pair well with lighter implements such as flail mowers, post hole borers, and small rotary hoes.
Double-Acting Hydraulic Circuit
A hydraulic connection that provides oil flow in both directions, allowing a ram to both extend and retract under power. Implements like hydraulic downforce post hole borers and grapple attachments require a double-acting circuit from the tractor's remote hydraulic outlets. Check your tractor's hydraulic specs before purchasing implements that need this type of circuit.
Flail Mower
A PTO-driven mower that uses free-swinging blades (flails) mounted on a horizontal rotor to cut grass, scrub, and light brush. Flail mowers produce a finer cut than rotary slashers and handle uneven ground well, making them a popular choice for paddock maintenance and roadside mowing. They are available in a range of working widths to suit different tractor sizes.
Front End Loader (FEL)
A hydraulic lifting arm assembly mounted to the front of a tractor, used for scooping, lifting, and carrying materials. A FEL accepts a range of attachments including buckets, pallet forks, bale grabs, and concrete mixers. Lift capacity and the type of quick-attach coupler are the main specs to check when adding attachments to your loader.
Gearbox
The enclosed gear assembly on a PTO-driven implement that converts the PTO shaft's rotation into the output speed and torque the implement needs. Post hole borers, wood chippers, and rotary hoes all rely on a gearbox to function properly. Gearbox ratio, oil level, and condition are important maintenance considerations for long implement life.
Grader Blade
A rear-mounted blade implement used to level, shape, and maintain gravel driveways, tracks, and farm roads. The blade angle can usually be adjusted to push material to one side. Grader blades attach via the three-point linkage and come in various working widths to match different tractor sizes.
Hydraulic Downforce
A hydraulic system fitted to some post hole borers that applies additional downward pressure on the auger to help it penetrate hard, rocky, or clay soils. Without hydraulic downforce, the operator relies solely on the weight of the implement to push the auger into the ground. This feature requires a double-acting hydraulic circuit on the tractor.
Large Tractor
A tractor typically rated above 100 HP, suited to broadacre farming and heavy-duty work. Large tractors generally use Category 2 or Category 3 three-point linkage and may run a 540 or 1000 RPM PTO. They are matched with heavy implements such as large flail mowers, cultivation equipment, and wide grader blades.
Lifestyle Block
A New Zealand and Australian term for a small rural property, typically between 1 and 20 hectares, used for hobby farming, grazing a few animals, or semi-rural living. Lifestyle block owners are a key audience for compact tractor implements such as post hole borers, flail mowers, and grader blades. The term is widely used across the Australasian rural property market.
Linkage Category
The ISO 730 size classification of a tractor's three-point hitch, ranging from Category 0 (sub-compact) through to Category 4 (large industrial tractors). Each category specifies pin diameters, lift arm spacing, and PTO shaft size. Matching your tractor's linkage category to the implement's category is essential for safe and proper fitment.
Lower Link Arms
The two outer arms of the three-point linkage that carry the implement's weight and connect to the lower hitch pins on the implement frame. They are raised and lowered by the tractor's hydraulic system. Pin diameter on the lower link arms corresponds to the linkage category of the tractor.
Medium Tractor
A tractor size descriptor generally covering the 60 to 100 HP range, sitting between compact and large classes. Medium tractors typically use Category 2 linkage and a 540 RPM PTO, though some offer 1000 RPM as well. They handle a broad range of implements including mid-size flail mowers, rotary hoes, and fertiliser spreaders.
Post Hole Borer
A PTO-driven implement fitted with an auger bit for drilling fence post holes quickly and consistently. Post hole borers mount to the three-point linkage and are available with features such as hydraulic downforce for tough ground conditions. Auger bit diameter is selected based on the post size you need to set.
PTO
Short for Power Take-Off, the PTO is a splined output shaft on the rear (or sometimes front) of a tractor that transfers engine power to drive an attached implement. It is the primary power source for flail mowers, wood chippers, rotary hoes, post hole borers, and many other implements. PTO shafts commonly spin at either 540 or 1000 RPM depending on the tractor.
PTO Driveshaft
The telescoping shaft with universal joints that connects the tractor's PTO stub to the implement's gearbox input. It transmits rotational power from the tractor to the implement and must be correctly sized in length and spline count. PTO driveshafts should always have their safety guards in place during operation.
PTO HP
The horsepower measured at the tractor's PTO shaft, as opposed to the engine's gross horsepower. PTO HP is always lower than engine HP because some power is lost through the drivetrain. When an implement lists a minimum HP requirement, it is almost always referring to PTO HP, so check your tractor's PTO HP rating before purchasing.
Rotary Hoe
A PTO-driven tillage implement that uses sets of rotating tines or blades to break up, mix, and cultivate soil. Rotary hoes are commonly used for garden preparation, seedbed finishing, and working organic matter into the ground. Working depth and working width are the two key specs to consider when choosing one for your tractor.
Shear Bolt
A sacrificial bolt designed to snap under excessive torque or impact, protecting the implement's gearbox and the tractor's PTO from costly damage. When a post hole borer hits a rock or a root, for example, the shear bolt breaks instead of the gearbox gears. Shear bolts are inexpensive and should be kept as spares on hand.
Skid Steer Quick Attach
An industry-standard coupler plate system that allows front end loader attachments to be swapped quickly without tools. By fitting a skid steer quick attach plate to your tractor's FEL, you gain access to a wide range of compatible attachments including buckets, grapples, pallet forks, and more. It is one of the most common attachment interfaces in the market.
Slip Clutch
An overload protection device fitted to a PTO driveshaft that slips when torque exceeds a preset limit, rather than breaking like a shear bolt. Slip clutches offer continuous protection and do not need replacement after each overload event. They are a popular upgrade on implements used in rough or unpredictable conditions.
Sub-Compact Tractor
The smallest class of tractor, typically rated under 25 HP, with Category 0 or Category 1 linkage. Sub-compact tractors are ideal for small lifestyle blocks, orchards, and property maintenance tasks. They pair with lighter implements such as small post hole borers, finishing mowers, and compact rotary hoes.
Three-Point Linkage
The standardised hitch system (governed by ISO 730) used to mount rear implements to a tractor. It consists of two lower link arms and an adjustable top link, forming a three-point connection that allows the tractor's hydraulics to raise, lower, and control the implement. Nearly all rear-mounted implements, from flail mowers to grader blades, connect through this system.
Top Link
The upper centre arm of the three-point linkage, connecting the tractor to the implement's top mounting point. By adjusting the top link's length, you control the pitch angle of the implement, which affects cutting depth, blade angle, or auger alignment. Correct top link adjustment is essential for safe and effective implement operation.
Tractor Overall Width
The total width of the tractor measured at its widest point, including tyres or mudguards. This measurement is important when selecting implements such as flail mowers and rotary hoes, because the implement's working width should generally match or slightly exceed the tractor's overall width for full coverage. It also matters for gate clearance and transport on narrow rural roads.
Utility Tractor
A mid-range tractor class typically rated between 45 and 100 HP, built for a wide variety of farm tasks. Utility tractors commonly use Category 2 linkage and a 540 RPM PTO. They are a versatile match for implements such as fertiliser spreaders, flail mowers, and rotary hoes.
Working Depth
The maximum or adjustable depth at which a ground-engaging implement operates below the soil surface. For a rotary hoe, working depth determines how deep the tines cultivate; for a post hole borer, it indicates how deep the auger can drill. This spec is set by adjusting the implement or selecting the right auger bit length.
Working Width
The effective cutting, tilling, or operating width of an implement, measured across the active area. For a flail mower, it is the width of the mowing deck; for a grader blade, it is the blade length. Matching working width to your tractor's overall width and to the job at hand ensures efficient coverage without overloading the tractor.