Grasscool 42-inch Mulching Blades for John Deere D100 D110 D130 — GY20850, 21-3/8" 7-Point Star

Grasscool GY20850 replacement mulching blades are heavy-duty 42" mower blades engineered to fit many John Deere D- and LA-series lawn tractors and deliver reliable mulching performance.

These Grasscool mulching blades are purpose-built to match the length, thickness, and center-hole pattern of common 42-inch John Deere decks so you can restore cutting and mulching efficiency without altering your mower. The blades measure 21-3/8" (543 mm) long, 2-23/32" (69 mm) wide, 5/32" (4 mm) thick with a 7-point star center hole and a 7/8" (22.5 mm) air lift. They are sold as direct-fit replacements for listed John Deere part numbers and model families; confirm your mower’s deck size and blade mounting pattern before ordering.

Which John Deere models are compatible with these Grasscool blades?

These mulching blades are designed for 42" decks used on many compact and lawn tractor models. They list compatibility across two-letter model families and individual model numbers, but compatibility is determined by deck size and the blade’s center-hole pattern.

• Compatible model groups: D100, D105, D110, D120, D125, D130 and LA100–LA135 series.
• Also fits select models labeled 102, 105, 115, 125, 135, E100/E120, S100/S120, X125.
• Confirm a 42" deck and the 7-point star center hole on your existing blade before purchase.

What are the exact blade dimensions and mounting details?

The Grasscool GY20850 replacement blade follows precise measurements so it mounts correctly and maintains the mower’s cutting geometry. Knowing these numbers helps you verify fitment against your current blades or owner’s manual.

• Blade length: 21-3/8" (543 mm).
• Width: 2-23/32" (69 mm); thickness: 5/32" (4 mm).
• Air lift height: 7/8" (22.5 mm) to support mulching action.
• Center hole: 7-point star pattern for correct spindle fitment.

How do these mulching blades affect mowing and maintenance?

Mulching blades are shaped to re-cut clippings and distribute them finely back into the turf, reducing bagging and improving grass return. These replacement blades are built to match the original profiles so deck balance and cutting quality remain consistent when installed correctly.

• Designed to re-chop clippings for a finer spread across the lawn.
• Maintain deck balance when installed in proper quantity and orientation.
• Painted finish protects against rust during storage and handling.

Are there installation or pre-use notes I should know?

Installation is straightforward but always requires safety precautions: disconnect the spark plug, stabilize the mower, and use proper fasteners. The blades come with a protective paint that does not need to be removed before operation; it wears off quickly once in use.

• Safety first: disconnect spark plug and support mower before working under the deck.
• Do not remove paint prior to installation — it prevents handling rust and fades with use.
• Double-check replacement number, head pattern, and blade length match your original blades.

Who is this for: Grasscool GY20850 mulching blades are intended for owners of John Deere lawn tractors and similar 42" deck mowers who need a like-for-like replacement to restore mulching performance. If you want blades that match OEM dimensions, a 7-point star center hole, and commercial-grade thickness for routine residential or light commercial mowing, these blades are a practical replacement—provided you confirm deck size and mounting pattern before buying.