Mulching Lawn Mower Blades Fit for 42" Decks, Compatible with John Deere M127129 M139802 M145969, S cotts S1642 S1742, Sabre 1542GS 15542HS 1842GV, 2 Pack

What It Is

This is a 2-pack of aftermarket mulching blades designed for 42-inch cutting decks. They fit select John Deere, Scott’s, and Sabre lawn tractors, intended to chop grass clippings finely for natural fertilization.

Fitment & Compatibility

• Deck size: Only for 42-inch decks. Measure your deck width (cutting swath) to confirm—do not assume from model number.
• OEM cross-reference: Replaces John Deere part numbers M127129, M139802, M145969. Check your owner’s manual or existing blade for these numbers.
• Brand/models: Listed for John Deere (unspecified series), Scott’s S1642, S1742, and Sabre 1542GS, 15542HS, 1842GV. Verify your model tag under the seat or on the frame.
• Measurements: Measure your blade length, center hole diameter, and thickness. Common specs for 42" decks: blade length ~20.5–21 inches, 5-point star center hole, 0.25” thickness. If your blade has a different hole pattern (e.g., oval or round), this won’t fit.
• Aftermarket note: Not OEM John Deere. Expect possible balance or thickness variations—check before installing.

Key Things to Know

• Quality concern: Rating is 1.9/5 from only 3 reviews. Likely thin steel (under 0.20”) or poor heat treatment, leading to bending or dulling quickly.
• Installation: Mulching blades require the blade to be installed with the curved edge facing up (toward the deck). Use a torque wrench to tighten to 70–90 ft-lbs.
• Common gotcha: These may not fit all 42" John Deere decks—some use a different spindle or blade offset. Compare your old blade’s shape (slight twist or flat) before buying.
• Pack size: 2-pack is typical for 42" decks (two blades per spindle). You get exactly what you need for one mower.

Should You Buy It

Only if you’re desperate for a quick, cheap replacement and have verified every measurement against your existing blade. With a near-1-star rating and no known quality reputation, you’re better off spending $5–10 more on a known aftermarket brand (e.g., Oregon or Stens) that offers consistent balance and steel hardness. Avoid for regular use on heavy or wet grass.