42 Inch Mower Blade for John Deere, Mulching Lawn Mower Blades for John Deere 42'' Deck with Circle Hole L100 L110 L111 L108 L118 Lawn Tractor Replace GX20249 GX20433 GY20567

What It Is

This is a set of three 42-inch mulching blades designed for John Deere lawn tractors with a 42-inch deck. They replace OEM part numbers GX20249, GX20433, and GY20567, and are intended for mulching grass clippings into fine particles that decompose quickly.

Fitment & Compatibility

Before buying, verify three things:

• Deck size: Must be exactly 42 inches (measured blade tip to tip). Measure your deck or existing blades—this set fits John Deere 42" stamped and fabricated decks.
• Model list: Confirmed for L100, L110, L111, L108, L118, plus similar models like D100, D110, D120, D130, D140, D150, D155, D160, and X100 series. Check your tractor’s model number under the seat or on the frame.
• Center hole: These have a round center hole (not a star or oval). Measure your spindle’s center hole diameter—should be 5/8” or 7/8” depending on the model. If your deck uses a star-shaped hole, these won’t fit.
• OEM cross-reference: Direct replacements for John Deere GX20249, GX20433, and GY20567. Aftermarket set, not OEM—quality is fine for typical residential use.

Key Things to Know

• Installation: Easy swap with a socket wrench and blade removal tool. Lift the deck, block it safely, and note blade orientation (cutting edge faces up when installed). Torque to 45–55 ft-lbs.
• Mulching vs. bagging: Designed for mulching—they have a higher lift and more aggressive curve to recirculate clippings. If you bag or side-discharge often, these may not perform as well as standard blades.
• Balance: Aftermarket blades sometimes need balancing. Check with a blade balancer before installing to avoid vibration. If unbalanced, file the heavy side slightly.
• Durability: Made of heat-treated steel—good for 20–30 mowings on a typical lawn. Sharpen or replace when edges dull or chip.

Should You Buy It

Buy this if you own a John Deere 42-inch deck tractor (L100 series or similar) and primarily mulch your lawn. At $28.99 for a set of three, it’s a solid value for regular replacement—just confirm your center hole type and balance before install. Skip it if your deck has a star center hole or you need bagging-specific blades.