New Stens 300-526 Mulching Blade Center Hole 3/8", Thickness 0.149", Width 2 1/4", Outer Hole 3/8" x 1 7/16", Length 20" Jacobsen 554589 for Lawn Mowers

What It Is

The Stens 300-526 is a 20-inch mulching blade designed primarily for Jacobsen and other commercial or residential lawn mowers. It replaces OEM part Jacobsen 554589, optimized for cutting grass into fine clippings that decompose quickly as natural fertilizer.

Fitment & Compatibility

Before buying, verify these four measurements:

• Center hole: 3/8-inch diameter (fits most standard spindle shafts)
• Outer hole pattern: 3/8-inch x 1 7/16-inch (center-to-center distance between two outer mounting holes)
• Blade thickness: 0.149 inches (common for mid-duty mowers)
• Blade width: 2 1/4 inches (matches many Jacobsen 20-inch deck models)

This blade is a direct replacement for Jacobsen 554589 but also fits other brands with the same hole pattern and 20-inch length. Check your mower’s deck size (must be 20-inch or larger) and spindle shaft diameter (must accept 3/8-inch center hole). If your mower uses a different hole pattern or length, this blade won’t work.

Key Things to Buy

• Quality: Stens is a reputable aftermarket brand; this blade is made from heat-treated steel for durability, but it’s not as thick as heavy-duty commercial blades.
• Installation difficulty: Easy—remove the old blade, clean the spindle, and torque to manufacturer specs (typically 40-50 ft-lbs). Use a blade balancer after install to avoid vibration.
• Common gotchas: The mulching design has a higher lift than standard blades, which may cause bogging in wet or tall grass. Also, ensure your mower deck has a mulching kit or plug; this blade won’t work well with side-discharge or bagging setups.
• Wear check: Inspect for bends or cracks every season; mulching blades dull faster than standard blades.

Should You Buy It

If you own a Jacobsen mower with a 20-inch deck and need a reliable, affordable mulching blade that matches OEM specs, this is a solid choice. It’s best for homeowners or light commercial users who prioritize fine clippings over bagging efficiency. Avoid if your deck uses a different hole pattern or you require a heavy-duty blade for tough conditions.