Earthtec 42" M170642 Mower Blades — 2-Pack Boron Steel, Marbain Heat-Treated for John Deere X330 X350 X354 Z335M

Earthtec M170642 42" mower blades are a two-piece replacement set engineered with boron-enriched steel and a patented Marbain heat-treat process to deliver higher hardness, greater impact resistance, and longer life for compatible lawn tractors and zero-turn mowers.

These Earthtec blades are designed as direct-fit replacements for multiple 42-inch decks used on popular John Deere model lines such as X330, X350, X354, X370, X380 and Z-series Z335E/Z335M/Z345M/Z345R. Built from a steel blend including boron, carbon, and manganese, and finished with Marbain heat treatment, the blades aim to resist wear and maintain edge retention longer than conventional lawnmower blades. The set contains two blades (part number M170642) so you can refresh a multi-blade deck with matched components.

How do these blades improve durability compared with stock blades?

The Earthtec blades use a specially formulated alloy and an independently tested Marbain heat-treat process that increases surface hardness significantly over standard blades. That extra hardness reduces nicks and edge roll, extending time between replacements and improving cut consistency.

• Boron-enhanced steel for increased strength and wear resistance.
• Marbain heat treatment makes blades 25–40% harder than typical blades.
• Engineered for impact resistance to withstand small strikes and debris better.

Will these blades fit my mower model and deck size?

This 2-piece set is made to replace part number M170642 and fits a variety of 42-inch mower decks used on listed John Deere lawn and garden tractors and ZTrak mowers. Always verify both the part number and your mower’s center hole and mounting pattern before ordering.

• Compatible with: X330, X350, X354, X370, X380 tractors and Z335E, Z335M, Z345M, Z345R ZTrak mowers.
• Center mounting hole: 51/64"; blade width and thickness match OEM specs.
• Includes two blades to service multi-blade decks or keep a matched spare.

What are the exact dimensions and mounting details?

These replacement blades follow common OEM dimensions for 42-inch decks. The listing gives precise measurements so you can confirm fitment against your mower’s existing blade or owner manual.

• Overall cutting length per blade: 21.4 inches.
• Blade width: 3.0 inches; thickness: 0.156 inches.
• Center hole diameter: 51/64 inches to match factory mounting hardware.

How should I maintain or install these blades for best performance?

Install blades following the mower manufacturer’s torque and safety guidelines, replacing blades in matched pairs when required for balance. Keep blades clean, sharpened only as needed, and inspect after striking hard objects.

• Replace blades in sets to maintain deck balance and cut quality.
• Follow OEM torque specs for mounting bolts; use new hardware if corroded.
• Inspect regularly for bends, cracks, or excessive wear and service accordingly.

Who is this for: The Earthtec M170642 42" 2-pack is aimed at property owners, landscapers, and maintenance professionals who run John Deere 42" mowing decks and want a durable, OEM-fit replacement that prioritizes longer edge life and better impact resistance than standard blades. Choose this set if you need accurately sized blades, a proven heat-treated alloy, and a matched pair for multi-blade decks.