Arnold AYP 42-Inch Blade Set

What It Is

The Arnold AYP 42-Inch Blade Set is a three-blade replacement kit designed for 42-inch cutting deck lawn tractors, primarily used for residential mowing on standard turf and grass.

Fitment & Compatibility

Before buying, measure your existing blades—this set typically has a 3.5-inch center hole, 0.25-inch thickness, and a 2.75-inch blade length offset. It fits AYP (American Yard Products) brand tractors, including Craftsman, Husqvarna, Poulan, and Murray models with a 42-inch stamped deck. Check your deck’s blade bolt pattern—this set uses three blades, each with a single center bolt. Confirm your spindle bolt size (usually 5/8-inch or 3/4-inch) and that your deck isn’t a “high-lift” or “mulching” design unless you cross-reference the part number. Arnold part number 490-100-0030 is the direct OEM equivalent.

Key Things to Know

• Quality: Made from 0.25-inch thick hardened steel; sharp out of the box but may dull faster than premium brands like Oregon or Gator on tough terrain.
• Installation: Easy DIY—requires a socket wrench and blade removal tool (or a block of wood to lock the blade). Torque bolts to 70–90 ft-lbs.
• Common gotcha: The set includes three identical blades, but some decks use staggered lengths (check your old blades for a part number). Also, the “42-inch” refers to total cutting width, not blade length—each blade is approx. 14.5 inches long.
• Balance: Lightly balanced from factory; re-balance after sharpening to avoid vibration.

Should You Buy It

This is a solid budget-friendly choice for replacing worn blades on a standard 42-inch AYP tractor deck. If you have a high-lift or mulching deck, or cut thick/overgrown grass regularly, opt for a premium or specialized blade set instead. For basic residential mowing, it’s a reliable, affordable drop-in replacement.