Does your lawn look less like a carpet and more like a shaggy jungle? A sharp, correctly sized lawn mower blade is the secret weapon for a perfect cut. But when you own a standard walk-behind mower, you often find yourself staring at a confusing array of sizes. The 21-inch blade is the powerhouse for most residential yards, yet choosing the wrong one can lead to frustrating results—uneven cutting, missed clumps, and even damage to your machine.
Picking the right 21-inch blade is more than just matching a number; you need to consider blade shape, lift, and material. If you choose poorly, you waste time and fuel fighting your grass instead of enjoying a beautiful yard. This guide cuts through the confusion. We will break down exactly what makes a great 21-inch blade, whether you need a standard, mulching, or high-lift design.
By the end of this post, you will know precisely which blade type matches your mowing style and grass conditions. Get ready to stop guessing and start achieving that professional, striped finish you’ve always wanted. Let’s dive into the details of the perfect 21-inch lawn mower blade.
Top 21 Inch Lawn Mower Blade Recommendations
- 21 Inch Troy Bilt Mower Blade Replace number Troy Bilt MTD 942-0741A 942-0741 742-0741 742-0741A 742-04100 490-100-C089 742-04276 742-04276S 942-04276 942-04276S CC-742-0741 OEM-742-0741
- 942-0741A Mulching Blade Compatible with Troy-Bilt TB110 TB240 TB230 TB130 TB200 TB160 TB210 TB280ES TB320 TB115 TB220 TB360 TB105 TB120 TB125 TB130XP TB140 TB160XP TB270ES TB270XP TB290ES TB330 TB360ES TB370 21" Deck Walk Behind Push Mower
- BLADE SPECIFICATION: Length: 20 7/8″(531.5mm), Width: 2-1/4"(57mm), Thickness: 9/64"(3.4mm), Center Hole Shape: Bow Tie, For Deck Size: 21", Lift: 1-1/8"(28mm), Mower Blade Type: Mulching Blade.
- FIT TOUGH MOWING TASKS: The blade is very suitable for cutting overgrown weeds or clearing rugged terrain. You can sharpen the blade if you want to maintain a neat, even cut for normal lawns. The cutting edges are painted to prevent rust and protect your hands during installation. The paint will wear off as you mow the grass.
- 3-IN-1 BLADE: Serves 3 purposes (mulching, bagging, and side discharging) at the same time. Featuring numerous curves that cuts and re-cuts grass to smaller pieces, and recycles them back into the soil as nutrients to promote healthy lawn growth. Additionally, its high-lift increases the bagging capacity by 50%.
- Includes 1 mulching blade for many 21 in. cut MTD, Cub Cadet, Troy-Bilt, and Craftsman mowers. Must Match Current Blade OEM Number to insure exact fit.
- Replaces OEM #'s: 742-0741, 742-0741A ,742-04276, 742-04276S, 942-0641, 942-0741, 942-0741A 942-04276, 942-04276S, CC-742-0741; Craftsman CMXGZAM100067
- Fits Cub Cadet Models: CC Series- CC 46M, CC 46MZ, CC 46ES, CC 439, CC 469, CC 949, CC 94M, CC 98M, CC 98H, CC 98K, CC 99M, CC 989, CC 997ES, CC 999ES; SC Series- SC 100, SC 100 H, SC 100 HW, SC 300, SC 300 E, SC 300e, SC 300 HW, SC 500 EZ, SC 500 EQ, SC 500 HW, SC 500 Z, SC 700E, and SC 700 H; S/SR/SRC/SRE Series: S 621, S 621 SS, SR 621, SRC 621, SRE 621, SC 621, SC 621 E; and other models- MTD 214 IP, 214 KW, and PR 521.
- Fits Troy-Bilt Models: TB 105, TB 110, TB 115, TB 120, TB 125, TB 130, TB 130 XP, TB 140, TB 160, TB 160 XP, TB 200, TB 210, TB 220, TB 230, TB 240, TB 270 ES, TB 270 XP, TB 280 ES, TB 290 ES, TB 320, TB 330, TB 360, TB 360 ES, TB 370, TB 370 XP, TB 380 ES, TB 380 XP, TB 400 XP, TB 430 XP, TB 450 XP, TB449E, TB 490 XP; Tru-Cut- 100, 110; Tuff Cut- 200, 210, 220, 230; Pro-Cut- 300, 310, 320.
- CENTER HOLE: Bow Tie Center Hole Pattern. Diameter of Outside Hole is 5/16". Center to Center of outside Hole is 2.5"
- Fits For Troy Bilt Tb110 Blade, Replace number Troy Bilt Cub Cade Craftsman MTD 942-0741A 942-0741 742-0741 742-0741A 742-04100 490-100-C089 742-04276 742-04276S 942-04276 942-04276S CC-742-0741 CMXGZAM100067 OEM-742-0741.
- Fits For Troy Bilt 21 Inch Mower Blade, Compatible with Troy-Bilt TB110 TB240 TB230 TB130 TB200 TB160 TB210 TB280ES TB320 TB115 TB220 TB360 TB105 TB120 TB125 TB130XP TB140 TB160XP TB270ES TB270XP TB290ES TB330 TB360ES TB370; Craftsman M250 M110 M230 M140 M210 M100 M260 M105 M270 M115 M320 M310 Lawn Mower.
- AVOID MISTAKES: This 942-0741A blade is ONLY compatible with a Bow Tie spindle. Please check that your center hole pattern matches before purchasing to avoid installation issues.
- BLADE SPECIFICATION: Length: 21"(533mm), Width: 2-1/4"(57mm), Thickness: 9/64"(3.4mm), Center Hole Shape: Bow Tie, For Deck Size: 21", Lift: 1-1/8"(28mm), Mower Blade Type: Mulching Blade.
- FIT TOUGH MOWING TASKS: The blade is very suitable for cutting overgrown weeds or clearing rugged terrain. You can sharpen the blade if you want to maintain a neat, even cut for normal lawns. The cutting edges are painted to prevent rust and protect your hands during installation. The paint will wear off as you mow the grass.
- Designed to Fit Which Blade Models: Mower Blade Replace number for Husqvarna and Craftsman with 21 inch Deck. Replace OEM model including: 165833, 175064, 189028, 406712, 532175064,532165833, 532189028, 532406712
- Circle Mounting Pattern Center hole shape: Length: 21"(535mm), width: 2-1/4"(57mm), thickness: 0.15"(3.5mm). For deck size: 21 inch, lift: 1-1/8"(28.0mm). Mower Blade Type: Mulching Blade. Note to self: Please check that your centre hole pattern matches before purchase to avoid installation problems
- Aerodynamic Blades: The blades are designed with many curves to create a strong airflow as they cut, which propels the grass in a continuous cutting cycle, eventually turning it into finely chopped grass (50% more bagging capacity). This not only greatly increases the efficiency of cutting and returning the chopped grass to the soil as a nutrient, but also greatly reduces the risk of blade clogging
- Suitable for Tough Mowing: The blades are made from high-strength steel that has undergone advanced heat treatment to give the blades maximum hardness and durability, making them ideal for cutting weeds or clearing uneven terrain. The finished lawn cut with the blade is as neat and even as if it had been cut individually with scissors
- Excellent Performance: We subject our blades to a rigorous series of tests, including dynamic balance tests, Rockwell hardness tests, V-bend tests, blade chip tests, performance tests and field tests. The blade is also coated with paint (which wears off as you mow) for extra corrosion protection and to protect your hands during installation. All to make it your right hand man!
- REPLACEMENT OEM: MTD/Cub Cadet 742-04100, 742-0741, 742-0741A, 942-0741, 942-0741A, 742-04276, 742-04276S, 942-04276, 942-04276S, CC-742-0741, 490-100-C089; Craftsman CMXGZAM100067
- COMPATIBLE WITH 21 INCH DECK MOWER: CUB CADET: CC469, CC989, CC997ES, PR521, S621, S621SS, SC621, SC621E, SR621, SRC621, SRE621, CC439, CC949, CC94M, CC98M, PR521, CC46M, CC46MZ, CC94M, CC999ES, SC 100 H, SC 100, SC 100 HW, SC 700 H, SC 700, CC46ES, CC99M, CC98, CC98H, CC98K, 5521, 214 IP, 214 KW
- 942-0741A MOWER BLADE SPECIFICATIONS: Length: 20-30/32"(531.5mm), Width: 2-3/16"(55mm), Thickness: 9/64"(3.5mm), Air lift: 26/32"(20mm), Center Hole Shape: Bow Tie, Blade Type: Mulching Blade
- 3-IN-1 MOWER BLADE: Supports mulching, bagging, and side-discharging modes.The advanced multi-curve design finely chops grass clippings into nutrient-rich mulch, promoting a healthier lawn. Meanwhile, the integrated high-lift wing optimizes airflow to significantly improve bagging efficiency for a cleaner cut and easier collection
- Precision Cutting Performance: Our blades are meticulously crafted from 40MnB steel and rigorously tested to ensure consistent, precise cutting. Designed for effortless operation, they deliver a smoother, more efficient mowing experience. The cutting edge features a rust-resistant coating that protects hands during installation; this coating wears off naturally during use
- 942-0741A Mulching Blade OEM: CC-742-0741, 742-0741, 742-0741A, 942-0741, 942-0741A
- 942-0741A Mulching Blade Compatible with Troy Bilt 21 inch Deck Lawn Mower,Model # TB 105, TB 110, TB 115, TB 120, TB 125, TB 130, TB 130 XP, TB 140, TB 160, TB 160 XP, TB 200, TB 210, TB 220, TB 230, TB 240, TB 270 ES, , TB 270 XP, TB 280 ES, TB 290 ES, TB 320, TB 330, TB 360, TB 360 ES, TB 370, TB 370 XP, TB 380 XP, TB 380 ES, TB 400 XP, TB 430 XP, TB 450 XP, TB 490 XP
- 942-0741A Mulching Mower Blade Compatible with Riding Mower,Lawn Tractor,Walk-Behind, Push and Self-Propelled Mowers with a 21-inch Cutting Deck, (1995 - );for many brand Troy-Bilt, Cub Cadet, MTD, Craftsman, MTD Gold, Bolens, White Outdoor, Murray, Snapper, Yard Machines, Yard-Man and Huskee
- 942-0741A Mower Blade Specification:blade length 21"(533mm),air lift 1-1/8"(28mm),width 2-1/4"(57mm),thickness 9/64"(3.4mm),compatible deck size 21"
- 942-0741a Blade Center Hole Shape:Bow Tie,Mower Blade Type:Mulching Blade,Made from alloy steel, incorporating elements like chromium and molybdenum into high-carbon steel for enhanced strength, wear resistance, and rust prevention, ensuring a longer service life
- Same as Which Blade Models: Mower Blade Replace number Troy Bilt Cub Cade, Craftsman MTD. Specifically including: 942-0741A 942-0741 742-0741 742-0741A 742-04100 490-100-C089 742-04276 742-04276S 942-04276 942-04276S CC-742-0741 CMXGZAM100067 OEM-742-0741
- Which Mowers are Compatible:Compatible with Troy-Bilt Lawn Mower: TB110 TB240 TB230 TB130 TB200 TB160 TB210 TB280ES TB320 TB115 TB220 TB360 TB105 TB120 TB125 TB130XP TB140 TB160XP TB270ES TB270XP TB290ES TB330 TB360ES TB370; And compatible with Craftsman Lawn Mower: M250 M110 M230 M140 M210 M100 M260 M105 M270 M115 M320 M310
- Aerodynamic Blades: The blades are designed with many curves to create a strong airflow as they cut, which propels the grass in a continuous cutting cycle, eventually turning it into finely chopped grass (50% more bagging capacity). This not only greatly increases the efficiency of cutting and returning the chopped grass to the soil as a nutrient, but also greatly reduces the risk of blade clogging
- Blade Parameters: Center hole shape: Bow Tie.Length: 21"(533mm), width: 2-1/4"(57mm), thickness: 9/64"(3.4mm). For deck size: 21", lift: 1-1/8"(28mm). Mower Blade Type: Mulching Blade. Note to self: This 942-0741A blade is ONLY compatible with a Bow Tie spindle. Please check that your centre hole pattern matches before purchase to avoid installation problems
- Suitable for Tough Mowing: The blades are made from high-strength steel that has undergone advanced heat treatment to give the blades maximum hardness and durability, making them ideal for cutting weeds or clearing uneven terrain. The finished lawn cut with the blade is as neat and even as if it had been cut individually with scissors
- REPLACEMENT OEM: MTD/Cub Cadet 742-04100, 742-0741, 742-0741A, 942-0741, 942-0741A, 742-04276, 742-04276S, 942-04276, 942-04276S, CC-742-0741, 490-100-C089; Craftsman CMXGZAM100067
- COMPATIBLE WITH 21 INCH DECK MOWER: Troy-Bilt Models: TB110, TB230, TB240, TB130, TB210, TB320, TB220, TB280ES, TB115, TB200, TB160.
- 942-0741A MOWER BLADE SPECIFICATIONS: Length: 20-30/32"(531.5mm), Width: 2-3/16"(55mm), Thickness: 9/64"(3.5mm), Air lift: 26/32"(20mm), Center Hole Shape: Bow Tie, Blade Type: Mulching Blade.
- 3-IN-1 MOWER BLADE: Supports mulching, bagging, and side-discharging modes.The advanced multi-curve design finely chops grass clippings into nutrient-rich mulch, promoting a healthier lawn. Meanwhile, the integrated high-lift wing optimizes airflow to significantly improve bagging efficiency for a cleaner cut and easier collection.
- Precision Cutting Performance: Our blades are meticulously crafted from 40MnB steel and rigorously tested to ensure consistent, precise cutting. Designed for effortless operation, they deliver a smoother, more efficient mowing experience. The cutting edge features a rust-resistant coating that protects hands during installation; this coating wears off naturally during use.
The Ultimate Buying Guide for Your 21-Inch Lawn Mower Blade
Choosing the right 21-inch lawn mower blade makes a big difference in how your lawn looks. A good blade cuts cleanly, keeps your mower running smoothly, and lasts a long time. This guide helps you pick the perfect blade for your grass-cutting needs.
Key Features to Look For
When you shop for a 21-inch blade, keep these important features in mind:
- Blade Length: Make sure the blade is exactly 21 inches long from tip to tip. This is crucial for your mower to work correctly.
- Center Hole Shape: Check the hole in the middle where the blade attaches to the mower. It might be round, star-shaped, or have a specific offset. You must match this shape exactly to your mower’s spindle.
- Blade Type: Different blades cut grass in different ways.
Understanding Blade Types
High-Lift Blades:
These blades lift the grass up high before cutting it. They work best in thick or wet grass because they create strong airflow to move clippings out of the way.
Medium-Lift (Standard) Blades:
These are good for general, everyday mowing in normal conditions. They offer a balance between lift and bagging efficiency.
Low-Lift Blades:
These blades create less airflow. They are best for dry conditions or when you are mulching finely, as they don’t blow the clippings around too much.
Important Blade Materials
The material the blade is made from determines how sharp it stays and how long it lasts. Quality matters here.
- High Carbon Steel: Most good blades use high carbon steel. This material holds a sharp edge well, which means fewer sharpenings.
- Hardness (Rockwell Scale): Higher quality blades are heat-treated to be harder. A harder blade resists bending and chipping when it hits small sticks or rocks.
- Thickness: Thicker blades generally last longer than thin ones. They resist warping better under heavy use.
Factors That Improve or Reduce Blade Quality
Not all 21-inch blades are made equal. Some things make a blade better, while others make it wear out fast.
Quality Boosters:
- Balanced Manufacturing: A well-made blade is perfectly balanced. If a blade is unbalanced, your mower will vibrate a lot, which wears out the engine bearings faster. Always look for blades that state they are factory balanced.
- Sharpening Angle: The angle at the cutting edge affects the cut quality. A sharper, precise angle gives you a cleaner cut, preventing the grass tips from turning brown.
Quality Reducers:
- Soft Metal: Blades made from soft, cheap metal dull very quickly. You will be sharpening them constantly, or replacing them often.
- Poor Fit: If the center hole does not fit snugly onto the mower spindle, the blade wobbles. This wobbling damages your machine over time.
User Experience and Use Cases
How you use your mower should guide your blade choice.
The Weekend Warrior (Light Use):
If you only cut a small, flat yard once a week, a standard, medium-lift blade made of good carbon steel will serve you well for several seasons.
The Professional/Heavy User (Frequent Use):
If you mow large areas or very thick grass often, you should invest in a thicker, high-carbon blade, perhaps even a specialized “gator” or mulching blade. These handle heavy loads without bending.
Wet Grass Conditions:
Always use a high-lift blade when mowing damp grass. The increased airflow helps push the sticky grass out of the deck, preventing clogging and creating an even cut.
10 Frequently Asked Questions (FAQ) About 21-Inch Mower Blades
Q: How often should I replace my 21-inch blade?
A: You should check the blade for bends or deep nicks every 25 hours of use. If you hit a lot of hard objects, replace it immediately. If you only sharpen it, replace it after two or three sharpenings, depending on the blade thickness.
Q: Can I use a 20-inch blade on a 21-inch mower?
A: No, you should never use a blade that is the wrong size. A shorter blade will leave uncut strips of grass in the middle of your lawn swath.
Q: What is the difference between a standard blade and a mulching blade?
A: A standard blade cuts and throws the grass out the side or into a bag. A mulching blade has curved edges that chop the grass into tiny pieces multiple times before dropping them back onto the lawn.
Q: How do I know if my blade is balanced?
A: A balanced blade hangs level when you try to balance it on a nail through the center hole. If one side dips, it needs professional balancing or replacement.
Q: Can I sharpen a low-quality blade?
A: Yes, you can sharpen almost any metal blade. However, soft metal blades will lose their edge again very quickly after sharpening.
Q: Does blade thickness affect bagging?
A: Yes. Thicker blades often create more stable airflow, which helps push clippings into the bag efficiently, especially when using a high-lift design.
Q: What happens if I use the wrong center hole shape?
A: If the center hole shape is wrong, the blade will not attach securely to the engine spindle. This causes extreme vibration, which can quickly damage your mower’s engine.
Q: Is it better to buy OEM or aftermarket blades?
A: Original Equipment Manufacturer (OEM) blades are guaranteed to fit and match the manufacturer’s specifications. Good aftermarket blades can save money, but you must verify the material quality and center hole match.
Q: Should I use a high-lift blade in dry, short grass?
A: Using a high-lift blade in very short, dry grass can sometimes be overkill. It might blow too much dry dust and clippings around. A standard blade works fine in those easy conditions.
Q: What safety gear should I wear when changing the blade?
A: Always disconnect the spark plug wire first to ensure the mower cannot accidentally start. Wear heavy work gloves to protect your hands from sharp edges.