Mowers Defined

air-cooled engine – engines that circulate air through the chamber to carry heat away.

anti-scalp wheels – small rollers affixed to the bottom of the mowing deck to prevent deck from gouging the ground. Adjustable gauge wheels offer the same benefit but can be manually adjusted and set within a range of 3 inches.

automatic blade stop (ABS) – A safety feature that stops the blade automatically when a handle or foot pedal is released, but the engine keeps running. Required safety equipment available on all mowers.

bagging – the ability to take clippings and transport them from the cutting chamber via a chute to an attached bag that sits between the handles (or behind the riding mower). Placing the bag between the handles instead of on the side makes it easier to trim using either side of the mower.

deck size – the deck size refers to the width of the cutting chamber the blade operates in.

diamond mowing – mowing diagonally up and down a steep hill to compensate for a lack of mower traction and to give the cut lawn a neat appearance.

disc drive – with disc drive, a friction plate rides against a drive plate allowing the operator to change forward speeds without clutching (as required with gear drives).

electric start and back-up recoil – with electric start, operator uses key to start the engine instead of using a starter rope that needs to be manually pulled then recoils.

ergonomics – study of physical effects of operating power equipment on the body through vibration and forces exerted on areas such as wrists, arms and back.

front-mount – riding mowers with the cutting deck in front of the operator’s seat.

gauge – the measurement of thickness of steel, most commonly used in mower decks; the numeric measurement of the gauge of steel is inversely related to the width of the steel itself.

gear-drive – mowers where the drive wheels are powered by gears; requires shifting of gears by operators.

height-of-cut adjustments – ability to raise and lower the cutting height of the machine allowing operator to cut grass at optimum length.

horsepower – a unit for measuring the power of engines. One horsepower is equal to the force required to raise 33,000 pounds at the rate of 1 foot per minute.

hydrostatic drive – mowers with drive wheels that are powered by hydrostatic pumps; dual hydrostatic drive offers operators zero-turn radius capabilities.

independent suspension – a system of control arms and coil springs on the front or rear drive wheels allowing each wheel to move up and down independently, smoothing out rough, uneven turf.

liquid-cooled engine – engines that circulate a liquid, generally water, through the chamber to carry heat away.

mid-mount or belly mount – riding mowers with the cutting deck directly beneath the operator’s seat.

mulching – practice of cutting and recutting grass clippings in one pass over a lawn to minimize the size of the grass clippings and accelerate the rate at which the clippings decompose; this process is also referred to as grasscycling.

operator Presence Control (OPC, engine-kill system) – on all walk-behind mowers, a handle must be engaged to start the engine and, when the handle is released, automatically stops the engine. The "engine-kill mechanism" on most riding mowers is under the seat.

pistol grips – one method of steering walk-behind mowers; operator has right and left handles that apply braking pressure to the corresponding drive tires.

pivoting front frame or front axle – this feature allows all four wheels (or front axle wheels) to remain on the ground while the deck conform to the contours of the lawn, giving a smooth, even cut.

push and self-propelled – a push walk-behind mower requires the operator to manually push the machine without the benefit of a drive system. This type of mower is usually for flat lawns less than ½ acre. A self-propelled walk mower comes with an additional handle that, when engaged, operates a belt that makes transmission pull the machine along by driving the rear wheels. Self-propelled models are better for lawns more than ½ acre or lawns with hills.

rear discharge bagging – with a true rear discharge model, the clippings exit the cutting chamber via the rear of the deck directly into the bag that sits between the handles. Rear discharge bagging is excellent for bagging grass in geographic areas where the grass is often wet.

side discharge – cuts and transports grass clippings to side discharge chute attached on the right-hand side of mower. Chute evenly disperses clippings back into lawn.

slope angle/degrees –
1:1 = 100 percent = 45 degrees
2:1 = 50 percent = 26.6 degrees
2.2:1 = 40 percent = 21/8 degrees
3:1 = 33.3 percent = 18/4 degrees
(read: one to one (run vs. rise) equals a 100 percent slope and 45 degree angle)

smooth turn differential – on self-propelled walk mowers, it’s a gear mechanism that allows for smooth, tight turns without damaging the lawn. Essentially, when turning, one rear wheel remains stationary while the other wheels turn until turn/pivot is completed.

striping – the process of creating patterns in the turf while mowing.

thatch – long grass clippings that are not bagged or properly mulched and form a layer on the soil that may stunt new grass growth. Thatch can also result over time due to the natural defoliation of the lawn.

3-in-1 convertibility – mower is designed to be used in any of three operations: mulching, bagging and side discharge. Additional accessory kits may be required depending on model.

winrowing – the process of leaving a line of grass clippings after they are discharged from the mower deck.

zero-turn radius – the capability of some mowers to turn 180 degrees within their own radius; to be a true zero-turn machine, a mower must have dual hydrostatic pumps controlling the drive wheels independently; can be a walk-behind or riding mower.