MTD 942-04308A 21.23" Blade 42" Deck for Murray Troy-Bilt Yard-Machines Mustang XP Pony Horse Bronco 670G 775S 795S 135

What It Is

This is a 21.23-inch replacement blade for 42-inch cutting decks used on Murray, Troy-Bilt, Yard Machines, and select MTD-branded lawn tractors. It’s designed for side-discharge and mulching applications on mid-duty residential mowers.

Fitment & Compatibility

Before buying, confirm three things:

• Deck size: Must be exactly 42 inches. Measure your deck or check your mower model number (e.g., Mustang XP, Pony, Horse, Bronco, 670G, 775S, 795S, 135).
• Blade length: 21.23 inches center hole to tip. Measure your old blade; even a 1/8-inch difference can cause imbalance or deck damage.
• Mounting: Fits a standard 1-inch center hole with a 5-point star drive (common on MTD spindles). Verify your spindle’s drive pattern—some older decks use a keyed oval hole.

This is an OEM-style replacement (Troy-Bilt/MTD part number 942-04308A). Aftermarket equivalents exist but may vary in thickness (0.1875 vs 0.204 inch) or heat treatment. Stick with OEM if you want exact fit.

Key Things to Know

• Quality concerns: The 2.6-star rating (4 reviews) suggests inconsistent sharpness or balance out of the box. Check for warping or burrs before installing.
• Installation: Use a torque wrench—spec is 70–90 ft-lbs. Over-tightening can strip the spindle; under-tightening causes wobble and poor cut.
• Common gotcha: This blade is not universal for all 42-inch MTD decks. Models like the 670G/775S/795S use a specific offset (0.5-inch lift) that differs from standard 42-inch blades. If your deck has a deep-dish spindle, you may need a different part.
• Mulching vs bagging: Works for both, but mulching performance is average. If you mulch heavily, consider a dedicated mulching blade with more lift.

Should You Buy It

Buy this only if you’ve confirmed your mower model and spindle type match exactly and you’re comfortable checking blade balance yourself. The low rating and limited reviews make it a gamble for casual users—if you want a safer bet, cross-reference the OEM part number with a higher-rated aftermarket brand (e.g., Oregon or Stens) that lists the same specs.