8TEN LawnRAZOR Blade for John Deere Z335E Z335M Z345M Z345R X380 X350 X370 X354 42" Deck M170642 (Mulching) 2 Pack

What It Is

The 8TEN LawnRAZOR Blade is a mulching blade designed for select John Deere zero-turn and lawn tractors with a 42-inch deck, including the Z335E, Z335M, Z345M, Z345R, X380, X350, X370, and X354 models. It replaces OEM part M170642 and is sold in a 2-pack for twin-blade decks.

Fitment & Compatibility

Before buying, confirm your mower has a 42-inch deck—this blade will not fit 48-inch or 54-inch decks. Check your owner’s manual or current blade for the OEM part number M170642. The blade measures 16.75 inches long with a 1-inch center hole and a 0.25-inch thickness. While it’s a direct aftermarket replacement for the listed John Deere models, verify that your deck uses a 2-blade configuration (not 3-blade) and that the blade’s offset matches your original (typically 0.5-inch lift). Measure your existing blade length and hole size to be safe—some older Deere decks may vary.

Key Things to Know

• Mulching vs. Standard: This blade has a more curved design and extra cutting edges to chop clippings finer for mulching. It will not discharge or bag as efficiently as a high-lift blade.
• Installation: Straightforward swap with a socket wrench. Use a torque wrench to tighten the blade bolt to 70-90 ft-lbs (check your machine’s spec). The blade is not reversible—install with the lift wings pointing up.
• Quality: LawnRAZOR blades are heat-treated and coated for rust resistance. Users report they stay sharp longer than OEM blades under moderate use, but may dull faster on rocky or sandy soil.
• Common Gotcha: The 2-pack covers one deck; don’t expect extra blades. If your deck uses a different blade offset or length (e.g., older X300 series), this won’t fit.

Should You Buy It

Buy this if you own a compatible John Deere 42-inch deck tractor and want a cost-effective mulching blade that performs well for regular lawn maintenance. It’s ideal for homeowners who prefer fine clippings over bagging and don’t need aggressive bagging or discharge capabilities. If you primarily bag leaves or cut tall, wet grass, consider a high-lift blade instead.