Caltric Deck Blade with Lock Nut Compatible with John Deere 102 105 115 125 135 100 Series 42" Tractor

What It Is

This is a 42-inch replacement blade set with lock nuts for John Deere 100 Series lawn tractors (models 102, 105, 115, 125, 135). Designed for standard residential mowing, it replaces worn or damaged factory blades.

Fitment & Compatibility

• Deck size: Only fits 42-inch cutting decks. Measure your deck width to confirm.
• Models: Compatible with John Deere 102, 105, 115, 125, 135, and other 100 Series tractors with a 42" deck. Not for larger decks or zero-turn mowers.
• OEM cross-reference: Replaces John Deere part numbers GY20785, GY20964, and GY21149. Verify your blade part number before ordering.
• Measurements: Blade length is 21 inches (center hole to tip). Center hole diameter is 0.75 inches. Blade thickness is 0.1875 inches. Confirm these match your current blade.
• Lock nuts included: Two lock nuts are supplied, but check that they fit your spindle shaft (typically 5/8" or 3/4" on these models).

Key Things to Buy

• Quality: Caltric blades are aftermarket, not OEM. They are generally well-reviewed for durability, but edge retention may be slightly less than factory John Deere blades.
• Installation: Easy—remove old blade, clean spindle, mount new blade with supplied lock nut. Torque to 35-45 ft-lbs. Use a blade removal tool or block of wood to prevent spinning.
• Gotchas: Blade orientation matters—the air lift side faces up. Check blade balance before installing (unbalanced blades cause vibration). The included lock nuts are single-use; replace them each time you swap blades.
• Packaging: Set includes two blades and two lock nuts. If your deck uses three blades, you need two sets.

Should You Buy It

If you need a budget-friendly, direct-fit replacement for a John Deere 100 Series 42" deck, this Caltric set works well for standard grass cutting. It’s a solid value for homeowners who want to save money over OEM blades. Not ideal for heavy-duty use or extremely rough terrain—consider OEM or high-lift blades for those conditions.