POSFLAG John Deere 42-Inch Replacement Mower Blades 2-Pack (GY20850) — Pre-Sharpened High-Lift Mulching with Nuts

These POSFLAG 2 Pack GY20850 blades are direct-fit replacement 42-inch John Deere mower blades with nuts, pre-sharpened and ready to install for reliable mulching and discharge performance.

When your mower’s cutting performance drops, swapping in a matched pair of blades restores clean cuts and efficient grass handling. POSFLAG engineered this two-blade kit to match common John Deere part numbers and deck dimensions, giving you a straightforward replacement that fits many 42-inch models. Each blade arrives heat-treated and pre-finished so you can get back to mowing quickly without extra sharpening or modification.

How do these blades improve cutting on overgrown or wet grass?

The high-lift geometry and sharp, pre-set edge on these blades lift and slice grass more effectively, reducing tearing and improving bagging or side discharge. Improved airflow helps move clippings through the deck and into the bag or out the chute, lowering the risk of clogs in dense or damp conditions.

• High-lift profile promotes stronger suction and cleaner discharge
• Pre-sharpened edges cut rather than crush grass for a neater finish
• Heat-treated high-carbon steel resists edge dulling under heavy use
• Designed to reduce clogging when mowing taller or wetter lawns

Will these blades fit my John Deere 42-inch deck and hardware?

POSFLAG blades are made to replace multiple OEM numbers—GY20850, GX22151, AM137333 and others—so they fit many common 42" John Deere decks without modification. The center hole uses the 7-point star pattern and the kit includes blade nuts so installation is complete out of the box.

• Blade center hole: 7-point star for direct compatibility
• Includes blade nuts and necessary hardware for quick swap
• Works with a long list of John Deere models and deck series
• Exact blade dimensions provided for verification before purchase

How easy and safe is the installation process?

Replacing these blades is a simple mechanical task: remove the old blades, align the new blade with correct cutting-edge orientation, and torque the included nuts to secure. Blades arrive pre-finished with a protective coating that wears off during initial use; follow standard mower safety steps and manufacturer torque specifications.

• Install in minutes with common hand tools—no cutting or mod needed
• Pre-sharpened so no immediate grinding required
• Safety coating peels naturally during first mowing
• Follow mower manual for recommended torque and safety procedures

What are the precise blade specs and construction details?

These mulching blades measure 21-7/16" long, 2-11/16" wide and 0.17" thick, with a 0.6" air lift designed to aid grass circulation under the deck. Constructed of heat-treated high-carbon steel, they balance toughness with a cutting edge that holds up in repeated use.

• Length: 21-7/16"; width: 2-11/16"; thickness: 0.17"
• Blade air lift: 0.6" for improved clipping handling
• Material: heat-treated high-carbon steel for durability
• Comes as a 2-pack so you can replace both blades at once

Who is this for: homeowners and landscapers who need an economical, OEM-compatible blade set to restore a 42-inch John Deere mower’s cutting quality. If you maintain multiple machines or prefer replacing blade pairs for balanced performance, this POSFLAG kit provides ready-to-install blades and hardware designed to match common John Deere part references and deck fittings.