Oregon 191-139 John Deere Replacement Lawn Mower Blade 21-3/8"

What It Is

The Oregon 191-139 is a 21-3/8-inch replacement blade designed for John Deere walk-behind mowers, typically used for residential lawn cutting. It’s a universal-fit aftermarket blade that replaces OEM John Deere part numbers, offering a budget-friendly alternative to factory blades.

Fitment & Compatibility

Before buying, verify three things:

• Deck size: This blade fits mower decks that accept a 21-3/8-inch blade length. Measure your current blade from tip to tip—if it’s not exactly that, this won’t fit.
• Center hole and mounting: The 191-139 has a 7/8-inch center hole and a 1-inch diamond-shaped center hole (common on John Deere). Check your blade’s center hole shape and size; if it’s round or a different diamond pattern, it won’t match.
• Brand/model: Listed for John Deere models like JS63, JS65, JS70, and others with 21-3/8-inch blades. Confirm your mower’s model number against Oregon’s compatibility chart—don’t assume universal fit across all John Deere decks.
• OEM vs aftermarket: Oregon is a reputable aftermarket brand, but it’s not OEM. If your mower is under warranty or you need exact original specs, stick with John Deere branded blades.

Key Things to Know

• Quality: These blades are made from hardened steel and are sharp out of the box, but they’re thinner than some OEM blades—may wear faster on rocky or thick grass.
• Installation: Easy DIY job with a socket wrench and blade removal tool. Torque the bolt to 35-40 ft-lbs (check your manual).
• Common gotcha: The diamond center hole can be tight on some spindles—file it slightly if needed, but don’t force it. Also, balance the blade after installation (use a balancer) to avoid vibration and spindle wear.
• Price vs value: At $11.99, it’s a solid budget pick. Expect 1-2 seasons of normal use before replacement.

Should You Buy It

Buy this if you have a compatible John Deere walk-behind mower with a 21-3/8-inch blade and want an affordable, reliable replacement for regular mowing. Skip it if you need OEM specs for warranty, have a different deck size, or mow heavy-duty commercial turf where thicker blades last longer.