MTD Genuine Parts (490-100-M067 Mulching Blades-for 21-Inch Lawn Mowers (1995 and After) Fits Various Troy-Bilt, MTD, Yard Machines, and Other Top Models, Natural

Swapping a mower blade is one of those 10-minute upgrades that can change how your lawn looks for the next season. I put the MTD 21-inch mulching blade on a late-2000s 21-inch Troy-Bilt push mower (MTD family) and used it across a full stretch of summer mowing. Here’s how it fit, cut, and held up—and how it compares to the high-lift and “gator” style blades many folks consider.

Installation and fit

The star-shaped center hole is the quiet hero here. It indexed cleanly onto the spindle and made alignment straightforward, with zero slop once seated. I blocked the deck with a scrap 2x4, removed the old blade, and installed this one with the correct orientation (mulch fins facing up toward the deck). The bolt torqued smoothly and the blade tracked true. I checked balance on a simple cone balancer before mounting; mine was dead-on out of the box and required no touch-up.

A couple of quick tips if it’s your first time:
- Disconnect the spark plug before working under the deck.
- Note the blade rotation and fin direction before you remove the old one.
- Use your mower’s torque spec when tightening. Over-tightening can distort the crank flange, under-tightening is dangerous.
- After installation, tip the mower back upright and spin the blade by hand to ensure no interference.

Compatibility is always the question with replacement blades. This one is built for MTD-family 21-inch walk-behind mowers from the mid-’90s forward, and it’s a direct replacement for common MTD part numbers (like 942-0741 variants). On my Troy-Bilt, the fit was as precise as the original.

Build and edge out of the box

The blade steel feels appropriately stout with a thickness similar to the OEM unit it replaced. Out of the packaging, mine arrived sharp with a clean factory grind and no burrs. The cutting edge isn’t razor-like—nor should it be—but it was primed for clean cuts without immediate sharpening. As with any shipped blade, it’s worth a quick inspection for nicks; a couple of passes with a file can correct minor handling marks.

Mulching performance

As a 3-in-1 profile, this blade balances lift and recirculation. In dry grass at normal weekly mowing height (taking off roughly 1/3 of the leaf), it produced fine, even clippings that disappeared into the turf without visible clumps. The deck stayed relatively clear with minimal buildup after several passes, which tells me the aerodynamic profile is doing its job keeping air moving without overloading the mower.

Push the blade into heavier work—damp grass or a missed week—and performance shifts to “good” rather than exceptional. It still breaks clippings down enough for a tidy finish, but you’ll see some strands in the canopy and need a slightly slower walking pace to keep up with the recirculation. Compared to more aggressive, toothed mulching blades, this one sacrifices a bit of that ultra-fine, coffee-ground finish in exchange for smoother airflow and better bagging.

Bagging and side discharge

The upside of this moderate mulching profile is versatility. Bagging is excellent. Suction at the deck lip is strong enough to collect stray leaves and seedheads without choking the chute, and the fill is even across the bag. I ran a couple of leaf-cleanup passes in late summer and had no clogging issues. Side discharge is similarly competent: it throws a consistent windrow and handles taller patches better than an aggressive mulcher that can stall airflow.

If your lawn care routine alternates between mulching and bagging depending on conditions, this blade hits a sweet spot. If you strictly mulch and want the smallest possible particles every time, there are more specialized profiles that beat it in that single category.

Cut quality

A good blade should cut, not tear, and turf health pays the price if the edge is wrong. With this one, the grass tips were clean post-mow under a quick inspection—no whitening or frayed edges that signal tearing. That held up for several weeks before I did a light touch-up with a file. On cool-season grass, the after-cut look was crisp, with minimal stray stragglers even at a 2.75–3.0 inch deck height.

Engine load, noise, and vibration

Mulching blades sometimes bog small engines. On a 140cc Briggs & Stratton, this blade ran without complaint in typical conditions. In wet or overgrown spots, I needed to slow my pace to keep the RPMs steady—nothing unusual there. Noise levels were typical for a 21-inch deck; the blade whistle was modest and less “whooshy” than some high-lift sets. Most importantly, vibration was a non-issue. No rattle in the handlebar, no deck chatter, and no harmonic buzz at full song.

Durability and edge retention

I mowed across a mixed suburban yard with the usual hazards—exposed roots, occasional small twigs, and the stray pebble. The finish on the blade held up, and the edge stayed serviceable through a half-dozen weekly cuts before I touched it up. After a couple of unintentional rock kisses, it showed minor dings but sharpened cleanly with a file. If you’re mowing in sandy soil or routinely hit debris, plan on more frequent maintenance; the steel here behaves like a standard OEM-spec blade, not a hardened specialty edge.

Maintenance and sharpening

• Touch-up interval: Every 6–8 mows for typical suburban grass is a good cadence.
• Sharpening: A mill file or bench grinder works; keep the factory bevel angle, avoid overheating the edge, and finish with a balance check.
• Balancing: A simple cone or nail-in-the-wall test is fine. An unbalanced blade shortens bearing life and adds vibration.

Because this blade is reasonably priced, I can see the appeal of replacing annually rather than maintaining. That said, two or three sharpening cycles per season is easy and extends life considerably.

Who it’s for

• Homeowners with 21-inch MTD-family mowers who alternate between mulching and bagging.
• Anyone wanting a straightforward, OEM-style fit with predictable, balanced performance.
• Users who value clean bagging and solid all-around cutting over ultra-fine mulching in tough, wet conditions.

Who might look elsewhere:
- Those who strictly mulch tall or wet grass and want aggressive, micro-chopping performance. A toothed or high-lift mulching blade may be a better single-purpose choice.

Value

This blade hits the right value notes: consistent fit on compatible mowers, a true 3-in-1 profile, and reasonable durability. It’s not a specialty performance blade, but it also doesn’t carry that price or trade-offs. For a general-purpose replacement that you can install and forget, it’s priced and built appropriately.

The bottom line

The MTD 21-inch mulching blade installs easily, runs smooth, and delivers a clean, reliable cut across mulching, bagging, and side discharge. It favors balance over extremes—meaning excellent bagging and solid mulching in normal conditions, with predictable behavior when the grass is longer or damp. Edge retention is on par with OEM standards, sharpening is straightforward, and the star hub ensures a snug, repeatable fit.

Recommendation: I recommend this blade for most MTD-family 21-inch mower owners who want a dependable, all-around performer. It’s especially good if you split time between mulching and bagging or want OEM-like fit and vibration-free operation at a sensible price. If your priority is the most aggressive mulching possible in challenging conditions, consider a more specialized blade—but for everyday lawn care, this one earns a spot on the spindle.