MowerPartsGroup (2) Blades for AYP/Husqvarna 42" 138971-532138498

What It Is

This is a set of two replacement blades for 42-inch cutting decks on AYP (American Yard Products) and Husqvarna riding mowers. Designed for medium-duty residential mowing, they are direct replacements for OEM part numbers 138971 and 532138498.

Fitment & Compatibility

Before buying, verify these three things:

• Deck size: Must be 42 inches (measured blade tip to blade tip across the deck). This set will not fit 46-inch or 54-inch decks.
• Mounting pattern: Center hole is 5/8-inch diameter with a 7-point star (also called a “star” or “spline” center). Confirm your spindle uses this pattern, not a round hole with a separate key.
• Blade dimensions: Each blade is approximately 20.5 inches long, 2.5 inches wide, with a 0.25-inch thickness. Measure your old blade to match.
• Brand fit: Fits most AYP, Husqvarna, Poulan, Craftsman, and Murray mowers with a 42-inch deck and star center spindle. Not for older round-hole spindles or zero-turn models.

Key Things to Know

• Quality: These are aftermarket blades, not OEM. Expect thinner steel (0.25 vs. 0.27 inches on some OEM) and may wear faster on rocky or heavy grass.
• Installation difficulty: Easy if you have a socket wrench and a torque wrench. Torque the center bolt to 70-90 ft-lbs. Use a blade removal tool or block the blade to prevent spinning.
• Common gotcha: The star center must align perfectly with the spindle. If the blade wobbles or won’t seat, check for burrs on the spindle or blade. Never force it.
• Balance: Aftermarket blades often need balancing. Use a blade balancer before installing to avoid vibration that can damage the spindle or deck.

Should You Buy It

Buy this if you have a 42-inch AYP/Husqvarna riding mower with a star-center spindle and need a quick, budget-friendly replacement for routine mowing. Skip it if you mow tough conditions (rocks, thick brush) or want longer-lasting OEM steel—spend more on genuine Husqvarna blades for heavier use.