GY20850 42" Mulching Mower Blades for John Deere D105 D130 S100 S110 S240 LA115 X300 E100 E110 LA135 Replace GX22151 AM137328 AM137333 AM141033 GX21694 M149422 42 inch Deck Lawn(7-Point Star), Blue

What It Is

This is a 42-inch mulching blade set designed to replace OEM blades on select John Deere lawn tractors and zero-turn mowers. It uses a 7-point star center hole and is intended for cutting grass into fine clippings that decompose quickly, reducing bagging needs.

Fitment & Compatibility

Before buying, confirm your deck is exactly 42 inches (measured blade tip to tip). This set fits John Deere models like D105, D130, S100, S110, S240, LA115, X300, E100, E110, LA135, and others listed. It replaces OEM part numbers GX22151, AM137328, AM137333, AM141033, GX21694, and M149422. The center hole is a 7-point star (not a 5-point or 6-point)—measure your spindle’s star pattern if unsure. Check blade length: these are ~21 inches each. If your deck uses a different hole pattern or length, these won’t fit.

Key Things to Know

• Quality: These are aftermarket blades, not OEM John Deere. They’re made from hardened steel but may be slightly thinner or less balanced than genuine parts. Most users report good durability for residential use.
• Installation: Easy if you have a socket wrench and a block of wood to jam against the blade. Torque bolts to 40-50 ft-lbs. Always lift the deck or remove spark plug for safety.
• Common gotcha: The 7-point star must align perfectly—some spindles have a 5-point star or a hex, so verify before buying. Also, mulching blades have a higher lift curve; they’ll cut fine but may leave clumps in wet grass.
• Set includes: Three blades (for a 42-inch triple-blade deck). If your deck only uses two blades, this set is wrong.

Should You Buy It

If you own a compatible John Deere with a 42-inch deck and want affordable mulching blades for regular residential mowing, this set works well. It’s a solid value compared to OEM replacements, but avoid it if you need a different hole pattern, a different blade length, or if you’re mowing commercially where durability and balance are critical.