"Mowing blades" generally refer to the blades that are mounted in the center of the chassis of rotary mowers (including electric mowers, gas mowers and riding mowers) and rotate at high speed to perform cutting operations.
Here are some key facts about mowing blades:
Core functions:
Cuts grass blades: The sharp blades that rotate at high speeds cut grass stems.
Creates airflow: The shape and rotation of the blades create an updraft that makes the grass stand upright for a clean cut and blows the clippings into a bag or evenly spreads them on the lawn (if mulching or side discharge mode is selected).
Main types:
Standard straight edge blades: The most common and most economical type. Has a straight or slightly curved blade edge that provides a clean cut. Usually used to mow and maintain lawns in good condition.
High lift/fan blades: Blades designed with a more pronounced curvature or wing-like structure that can create a stronger updraft. Advantages: More efficient blowing of grass clippings into a bag, or more uniform mulching (grass clippings are cut multiple times and blown back onto the lawn). Disadvantages: Higher engine load when working on dense or wet grass.
Mulching blades: Blades designed specifically for mulching (often also high-lift designs). Characterized by longer blades, sometimes with extra fins or special shapes, the goal is to more finely cut grass clippings multiple times and then evenly spread them back on the lawn as a natural fertilizer.
Low-lift blades: Produce a weaker airflow. Mainly used to deal with heavy, wet or long grass, because the strong airflow may flatten wet grass instead of blowing it up. Also commonly used on mowers with a "grass mulcher" attachment.
Multi-purpose blades: Blade designs that combine standard cutting and mulching functions, trying to strike a balance between grass collection, mulching and side discharge.
Reinforced/heavy-duty blades: Made of thicker steel, more durable and more impact-resistant. Suitable for lawns with a few small branches, stones or uneven terrain. Usually more expensive.
3-in-1/2-in-1 blades: Claim to optimize grass collection, mulching, and side discharge simultaneously through special designs (such as additional cutting edges or wings).
Key parameters:
Length: Must match the chassis size of your mower exactly. Common home mower blade lengths are 16 inches, 18 inches, 19 inches, 20 inches, 21 inches, 22 inches, etc. Be sure to check the mower manual or the markings on the old blade before purchasing.
Center hole diameter and mounting hole style: The hole in the center of the blade must match the diameter of the mower spindle, and the location and number of mounting holes must also be consistent. Common ones include single hole, star hole, multiple holes, etc. Matching errors can result in failure to install or dangerous operation!
Thickness: Usually indicated by a number (such as .187, .250 inches). Thicker blades are more rigid, more durable, less likely to bend or break, but also heavier.
Material: Usually high-carbon steel, some high-end or heavy-duty blades use special alloy steel or are hardened to increase hardness and wear resistance.
Edge Types:
Single-Sided: Only one side is sharpened, the other side is flat. Need to distinguish the installation direction (the blade must face down).
Double-Sided: Both sides are sharpened. When one side becomes dull, you can turn it over and use the other side to extend the service life. The direction is not strict when installing (but there is usually still a recommended installation surface).
Maintenance and Replacement:
Sharpening: Blunt blades will cause uneven cutting, tearing of grass leaves (prone to disease), and increased fuel/power consumption. It is recommended to sharpen the blade 1-2 times per season. You can use a special blade sharpener, angle grinder (be careful) or take it to a professional repair shop. Key: Dynamic balancing must be performed after sharpening, otherwise it will vibrate violently when rotating, damaging the machine or even causing the spindle to break. Sharpening shops usually provide balancing services.
When to replace:
The blade is severely bent, deformed, cracked or has large gaps.
Excessive wear makes it impossible to sharpen effectively.
Even after sharpening and balancing, the mowing effect is still poor or the vibration is too large.
The blade is damaged by hitting a hard object (stone, tree roots, metal, etc.).
Replacement precautions:
Safety first! Always disconnect the spark plug wire (gasoline engine) or unplug the power supply (electric/battery engine) to ensure that the machine cannot be started accidentally.
Use a suitable socket wrench (usually a deep socket) and an extension rod to remove the fastening nut/bolt (usually reverse thread - loosen clockwise).
Record the installation direction of the old blade (especially single-sided blade) and install the new blade in the same direction.
Tighten the new blade bolt/nut according to the torque value specified by the manufacturer. Too loose will fly off, too tight will damage the thread.
When starting for the first time after replacement, let the mower idle for a while and check for abnormal vibration or noise.
Selection suggestions:
First principle: Buy strictly according to the size and mounting hole specifications required by the mower model.
Lawn condition:
Standard lawn: standard straight blade or multi-purpose blade.
Need to collect grass frequently: high lift blade.
Mainly used for mulching function: dedicated mulching blade.
Lawn is uneven or has small debris: reinforced/heavy-duty blade.
Grass is often long and wet: low-lift blade or reinforced blade.
Budget: Standard blades are the cheapest, reinforced blades and double-edged blades are usually more expensive.
Summary:
Mowing blades are one of the most core working parts of a lawn mower. Its type, size, sharpness and condition directly affect the cutting effect, grass clippings handling effect, machine efficiency and lawn health. Understanding the characteristics of different blades and regularly checking, sharpening or replacing damaged blades are important links to keep the lawn beautiful and maintain the performance of the mower. When replacing, be sure to confirm that the size and installation method are exactly matched to your mower model.
Audited Supplier 
){kind=link}