84005221 21"Lawn Mower Blade, Replace for 2105200317 2105200317A Push Mower Blade for Murray Daye Hyper Tough MNA152901 MNA152903, 2 Pack

What It Is

This is a 21-inch replacement lawn mower blade (2-pack) designed for push mowers, primarily fitting Murray, Daye, Hyper Tough, and similar brands. It replaces OEM part numbers 2105200317 and 2105200317A, and is intended for standard residential grass cutting on flat or mildly uneven terrain.

Fitment & Compatibility

Before buying, confirm three things:

• Deck size: This blade is exactly 21 inches long—measure your mower deck’s cutting width (usually stamped on the deck). It fits only 21-inch decks.
• Blade mount: Check your mower’s center hole size (should be about 1 inch) and the drive pin/star pattern. This blade uses a standard 5-point star center hole. If your mower has a different pattern (e.g., oval or diamond), it won’t fit.
• Model list: Verified compatible with Murray, Daye, Hyper Tough models like MNA152901, MNA152903, and push mowers using 2105200317/2105200317A. Not for riding mowers or zero-turns.

Key Things to Know

• Quality: Aftermarket blade, not OEM Murray. Made of stamped steel—adequate for typical residential use but may dull faster than premium heat-treated blades.
• Installation: Easy with a socket wrench. Remove spark plug wire first for safety. Torque blade bolt to 30–40 ft-lbs (check your mower manual). No special tools needed.
• Common gotcha: The blade is sold as a 2-pack, but some mowers use only one blade. Verify your mower’s blade count before ordering.
• Balance: Out of the box, these blades may be slightly unbalanced. Use a blade balancer or nail-in-wall trick to check—if off, file the heavy end slightly.

Should You Buy It

Buy if you need a budget-friendly, direct replacement for a 21-inch push mower with a standard star mount and you’re okay with aftermarket quality. Skip if you want OEM durability, have a different blade mount, or mow thick/wet grass frequently (consider a high-lift or mulching blade instead).