UDC Parts 42" Replacement Mower Blades for John Deere 7-Point Star Mount — 2-Pack, 42" Deck Mulching Performance

UDC Parts 2-pack replacement mower blades are 42-inch, 7-point-star-mount John Deere-compatible blades engineered for reliable cutting and mulching on a wide range of 42" decks.

These replacement blades from UDC Parts are made to match the fit and cutting geometry of several John Deere OEM numbers (GY20850, GX22151, AM141033 and more). Each blade measures 21-3/8" diagonally, has a 7-point star center mounting pattern and an air-lift profile to improve grass lift and even discharge. They come as a two-piece set so you can refresh both cutting edges at once and restore a cleaner, more uniform cut to your lawn tractor's 42" deck.

Which John Deere models and OEM numbers do these blades replace?

These UDC blades are designed to replace many common John Deere part numbers and fit a broad list of lawn tractor models using a 42" deck with a 7-point star spindle. They cover several OEM codes so they are a practical aftermarket option for owners of different model series.

• Direct OEM replacements: GY20850, GX22151, AM141033 (plus UC21583, AM137333, AM141034, and others).
• Compatible model families: D100/D110/D120/D125/D130 series, S100 series, E100/E110/E120/E130, LA100–LA135, X100–X145, X300/X500 series with specified 42" Edge or 42C decks.
• Specifically fits tractors that use a 7-point star spindle mounting pattern.

How do I confirm these blades will fit my mower?

Measure and verify your deck and spindle before ordering. Blades may vary across years and optional decks, so checking dimensions and mounting type is essential to ensure compatibility.

• Confirm deck size is 42" and blade length measures approximately 21-3/8" diagonally.
• Verify center hole is the 7-point star pattern used by the spine/spindle on your mower.
• Cross-check your tractor’s exact model number and any deck suffix or production range referenced in your owner’s manual.

What are the key blade dimensions and design features?

These replacement blades have specific measurements and a profile optimized for lift and mulching action, designed to work with the airflow geometry of many John Deere 42" decks.

• Overall diagonal length: 21-3/8"; width: 2-3/4"; cutting edge length: 5-7/16".
• Center mounting: 7-point star; air lift height: 1" for better grass lift.
• Supplied as a two-blade pack so both sides of the deck have matched edges and balance.

What should I expect when using these blades on my lawn?

When properly installed and balanced, these UDC replacement blades restore cutting performance and help produce a more even discharge or mulched finish. They are manufactured to the dimensional standards required for the listed John Deere applications.

• Sharper, more consistent cutting across the 42" swath when blades are balanced and installed correctly.
• Improved lift and grass circulation due to the air-lift profile, aiding mulching and discharge performance.
• Sold as a 2-pack to ensure both blades on the deck match for reduced vibration and improved cut quality.

Who is this for: These UDC Parts replacement blades are ideal for homeowners and groundskeepers who own John Deere lawn tractors with a 42" deck that require a 7-point star mount—especially those replacing worn or damaged blades and seeking a cost-effective aftermarket option that matches multiple OEM numbers. If you’re unsure about fitment, confirm your model, deck type, and spindle mounting pattern before purchasing to avoid returns.