Best Lawn Mower Blades for 21 Inch Deck: 5 Blades Compared
Five replacement mulching blades for 21-inch decks compared by length, center hole shape, pack size and stated warranty terms in detail.
On this page
Top picks at a glance
As an Amazon Associate I earn from qualifying purchases.
- 1
Best OverallOregon Gator G39.6/10View on Amazon - 2
Best 2-PackGICOOL 2-Pack Blade9.5/10View on Amazon - 3
OEM PickMTD 490-100-M0679.5/10View on Amazon - 4
Toothed MulchingGrasscool Toothed Blade9.4/10View on Amazon - 5
Bow-Tie FitDOCAS 2-Pack Blade9.4/10View on Amazon
The grass out by the fence is already tall enough to seed, and the mower is throwing uneven stripes across the lawn instead of a clean cut. Dull blades tear the grass instead of cutting it, so the best lawn mower blades for 21 inch deck start with a sharp edge that fits the mower you already own. We compared five replacement mulching blades for 21 inch decks by length, center hole shape, pack size, stated construction and warranty terms, using only what each listing publishes.
AcreMowerLab earns a commission when you shop through links here. It never changes your price. Affiliate disclosure.
Quick picks
- Best Overall Oregon Gator G3: 26-point certification and limited lifetime warranty stated Check price on Amazon
- Best 2-Pack GICOOL 2-Pack Blade: Two blades, 40MnB steel and full dimension specs stated Check price on Amazon
- OEM Pick MTD 490-100-M067: Genuine MTD parts for 1995 and later 21-inch mowers Check price on Amazon
- Toothed Mulching Grasscool Toothed Blade: Toothed mulching blade with stated air lift of 15/16 in Check price on Amazon
- Bow-Tie Fit DOCAS 2-Pack Blade: Two blades with bow tie center hole for 21-inch decks Check price on Amazon
Our acreage picks
Oregon Gator G3 21 in Mulching Blade for 21 in Decks
A 21 in Gator G3 mulching blade with a 5/8 in round center hole, a stated 26-point manufacturing certification and a limited lifetime warranty.
Who it's for: someone who wants a certified blade with a stated lifetime warranty for a 21 inch deck.
Who should skip it: anyone who wants a two-pack or a stated steel grade.
Read the full review
Oregon lists the Gator G3 as a 21 in mulching blade for 21 inch decks, made in the USA with a stated 26-point certification of manufacturing quality, a 5/8 in round center hole, dimensions of 2.5 by 21.15 in and a limited lifetime warranty covering defects in material and workmanship.
Pros
- 26-point manufacturing certification stated on the listing
- Limited lifetime warranty is included, per the listing
- Fits Arnold, AYP, Craftsman, Husqvarna and Poulan models
- Made in the USA is stated on the listing
Cons
- Only one blade in the pack, where two listings here include two
- 0.2 kg item weight is stated with no comparison given
- Blade width figure comes only from the spec table, not the bullets
- Metal material type is stated without a grade
GICOOL 942-0741A 21 in Mulching Blades, 2 Pack
A 2-pack of 21 in mulching blades in 40MnB steel with a bow tie center hole, a rust-resistant coating and the most detailed stated dimensions here.
Who it's for: someone who wants the most detailed spec sheet and a spare blade in the box.
Who should skip it: anyone who wants a stated warranty or a simpler fit list.
Read the full review
GICOOL lists a 2-pack of 21 in mulching blades in 40MnB steel with a bow tie center hole, a rust-resistant cutting edge coating and a 3-in-1 mulching, bagging and side discharge design, with the length stated as 20-30/32 in (531.5 mm), a 6-3/16 in edge, 2-3/16 in width and 9/64 in thickness. It lists replacement numbers across the MTD, Cub Cadet, Troy-Bilt and Craftsman families. No warranty term is stated.
Pros
- Two blades in the pack for a ready spare
- Full dimensions stated: 20-30/32 in length, 2-3/16 in width, 9/64 in thickness
- 40MnB steel with a rust-resistant coating stated
- Lists replacement numbers for MTD, Cub Cadet, Troy-Bilt and Craftsman
Cons
- No warranty term is stated
- 40MnB steel is stated without a certification
- Single-color black finish with no coating wear figure
- Long replacement-number list can confuse the wrong fit
MTD Genuine Parts 490-100-M067 21 in Mulching Blades
Genuine MTD mulching blades with a star center hole for 21 inch mowers built from 1995 on, covering mulching, bagging and side discharge.
Who it's for: an MTD or Troy-Bilt owner who wants the genuine part for a 1995-or-later 21 inch mower.
Who should skip it: anyone whose mower is older, or who wants a stated warranty.
Read the full review
MTD lists the 490-100-M067 as genuine mulching blades engineered for 21 inch mowers manufactured from 1995 on. The blades carry a star-shaped center hole for a sturdy fit on the shaft, and the listing describes a 3-in-1 design for mulching, bagging and side discharge. Compatibility covers Troy-Bilt, MTD, Yard Machines, Huskee and Bolens, with replacements for 942-0741, 942-0741A, 742-0741 and 742-0741A. Dimensions are stated as 21 by 2.25 by 1 in. No warranty term is stated.
Pros
- Genuine MTD parts for an exact-fit claim
- Star center hole for a sturdy fit on the shaft
- 3-in-1 design covers mulching, bagging and side discharge
- States fit for Troy-Bilt, MTD, Yard Machines, Huskee and Bolens
Cons
- No warranty term is stated in the listing
- Pack count is not stated as a number
- Blade width comes only from the dimension line
- Only lists fit for mowers made in 1995 and after
Grasscool 21 in Toothed Mulching Blade for Troy-Bilt and MTD
A 21 in toothed mulching blade with a 4 in cutting edge, 15/16 in air lift and a paint finish the listing says protects your hands.
Who it's for: someone who wants a toothed mulching edge with stated dimensions.
Who should skip it: anyone who wants a stated center hole shape or a warranty term.
Read the full review
Grasscool lists a 21 in toothed mulching blade for 21 inch decks on walk-behind, push and self-propelled mowers, replacing Cub Cadet, MTD and Troy-Bilt numbers including 942-0741 and 942-0741A. The listing states a 21 in length, 15/16 in air lift, 2-1/2 in width, 1/8 in thickness and a 4 in cutting edge. The paint protects your hands during installation and wears off in use. No warranty term is stated.
Pros
- Toothed mulching edge for finer clippings
- States air lift of 15/16 in and 4 in cutting edge
- Paint finish stated to protect hands during installation
- Lists replacement numbers for Cub Cadet, MTD and Troy-Bilt
Cons
- No warranty term is stated
- Pack count is not stated as a number
- Center hole shape is not stated
- 3.2 oz item weight seems light next to other listings
DOCAS 21 in Mulching Blades, 2 Pack, Bow Tie Center Hole
A 2-pack of 21 in mulching blades with a bow tie center hole for MTD, Cub Cadet, Troy-Bilt and Craftsman 21 inch decks.
Who it's for: someone who wants a bow tie fit and a spare blade for a common MTD-family deck.
Who should skip it: anyone who wants a stated warranty or the widest blade here.
Read the full review
DOCAS lists a 2-pack of 21 in mulching blades for walk-behind, push and self-propelled mowers with 21 inch cutting decks, covering MTD, Cub Cadet, Troy-Bilt and Craftsman models. The listing states a 21 in length, 2-1/5 in width and a bow tie center hole, and it replaces OEM numbers 742-04100, 742-0741, 742-0741A, 942-0741 and 942-0741A. No warranty term is stated.
Pros
- Two blades in the pack for a ready spare
- Bow tie center hole stated for the fit
- Lists OEM numbers 742-04100, 742-0741, 742-0741A, 942-0741 and 942-0741A
- 21 in length stated for 21 inch cutting decks
Cons
- No warranty term is stated
- Blade thickness is not stated
- 2-1/5 in width is narrower than two listings here
- OEM replacement list is shorter than the GICOOL listing
Side-by-side specs
| Blade | Acre Score | Type | Length | Center hole | Pack | Warranty |
|---|---|---|---|---|---|---|
| Oregon Gator G3 | 9.6/10 | Mulching | 21 in | 5/8 in round | 1 | Limited lifetime warranty |
| GICOOL 2-Pack Blade | 9.5/10 | Mulching 3-in-1 | 20-30/32 in (531.5 mm) | Bow tie | 2 | Not stated |
| MTD 490-100-M067 | 9.5/10 | Mulching 3-in-1 | 21 in | Star | Not stated | Not stated |
| Grasscool Toothed Blade | 9.4/10 | Toothed mulching | 21 in | Not stated | Not stated | Not stated |
| DOCAS 2-Pack Blade | 9.4/10 | Mulching | 21 in | Bow tie | 2 | Not stated |
Specifications are manufacturer rated as listed, collected 23 October 2026. One of the five states a warranty term.
Acreage and terrain fit
Oregon Gator G3
GICOOL 2-Pack Blade
MTD 490-100-M067
Grasscool Toothed Blade
DOCAS 2-Pack Blade
Buying guide: choosing the best lawn mower blades for 21 inch deck
Match the part number and the center hole
The center hole is what locks the blade to the mower shaft, and the five listings here show three shapes: a star hole on the MTD, bow tie holes on the GICOOL and DOCAS, and a 5/8 in round hole on the Oregon. Compare your old blade and the replacement numbers in the listing: the MTD replaces 942-0741 and 742-0741, while the GICOOL lists over a dozen MTD, Cub Cadet and Craftsman numbers. See our best type of mower blades guide.
Mulching, bagging or both
All five blades here are mulching blades. The MTD and GICOOL describe theirs as 3-in-1 blades that cover mulching, bagging and side discharge, while the Grasscool is a toothed mulching blade. The Oregon is a Gator G3 high lift mulcher aimed at mulching and side discharge. If your yard runs thick in summer, match the blade type to how you handle clippings, not just to the deck width. See our best lawn mower blade for push mower guide.
One blade or two
The GICOOL and DOCAS listings each include 2 blades, which gives you a spare ready to swap while the dull one waits for sharpening. The Oregon, MTD and Grasscool listings are single blades.
Check the stated dimensions
The listings state blade length, width and thickness in different levels of detail. The GICOOL states a 20-30/32 in length, 2-3/16 in width and 9/64 in thickness. The Grasscool states 21 in by 2-1/2 in by 1/8 in. The DOCAS states 21 in by 2-1/5 in.
Read the manual, keep children and pets out of the yard while you work, wear eye and hearing protection and sturdy footwear, and never exceed the slope rating of your machine. Refuel only with the engine off and cool. See CPSC lawn mower safety. Read our Safety Disclaimer.
Matching It to Your Property
- Flat open lawn: any of the five fits a 21 inch deck; pick by center hole shape and whether you want a spare.
- Lots with sticks and debris: the toothed Grasscool mulching blade states a toothed edge for mulching duty.
- Troy-Bilt and MTD walk-behinds: the MTD star-hole blade and the GICOOL and DOCAS bow tie blades list the MTD and Troy-Bilt part numbers directly.
- Storage: keep a spare blade from a 2-pack listing (GICOOL or DOCAS) ready so a dull edge never delays a mow.
The Acre Score explained
The Acre Score weighs performance (blade type, edge detail and stated cutting features), build (steel, dimensions and construction), value for the stated specs, safety and warranty. For blades, safety means a stated certification or safety feature on the listing; the Oregon states a 26-point manufacturing certification, the others state none. One listing states a warranty term: the Oregon with a limited lifetime warranty. How we pick explains the weights.
| Product | Acre Score | Perf. /35 | Build /25 | Value /25 | Safety /10 | Warranty /5 |
|---|---|---|---|---|---|---|
| Oregon Gator G3 | 9.6 | 32 | 21 | 21 | 0 | 4 |
| GICOOL 2-Pack Blade | 9.5 | 30 | 21 | 21 | 0 | 0 |
| MTD 490-100-M067 | 9.5 | 29 | 20 | 21 | 0 | 0 |
| Grasscool Toothed Blade | 9.4 | 28 | 20 | 20 | 0 | 0 |
| DOCAS 2-Pack Blade | 9.4 | 27 | 20 | 20 | 0 | 0 |
Scores run from 9.2 to 9.8: each product’s point total is placed on that range, so more points always means a higher score.
FAQ: mowing large lots
How do I know which blade fits my mower?
Match the replacement part numbers and the center hole shape: the MTD replaces 942-0741 and 742-0741, the GICOOL lists the 942-0741A family, and the Oregon fits Arnold, AYP, Craftsman and Husqvarna models.
What is a 3-in-1 mower blade?
The MTD and GICOOL listings describe their blades as 3-in-1, meaning one blade handles mulching, bagging and side discharge. The mower changes the mode, not the blade.
Do I need to remove the paint before using a new blade?
The Grasscool listing says no: the paint protects your hands during installation and prevents rust, and it wears off after a few minutes of mowing.
Is a two-pack of blades worth it?
The GICOOL and DOCAS listings each include 2 blades. A second blade lets you swap in a sharp edge and sharpen the dull one later.
What warranty comes with mower blades?
Only the Oregon listing here states one: a limited lifetime warranty covering defects in material and workmanship. The other four listings state no warranty term.
More mowing guides
- Best Mower Blade Sharpener for Lawn Tractors (2026)
- Best Type of Mower Blades (2026)
- Best Lawn Mower Blade for Push Mower (2026)
- Best Mower Blade Balancer Under $25 (2026): 5 Picks Compared
- Best Lawn Mower Blade for Bahia Grass (2026): 5 Picks Compared
- Best File for Sharpening Lawn Mower Blade: 5 Picks
- Riding Mower Maintenance: Step-by-Step Care Guide
