B1PD1042 J D Predator Blade 21-1/4"L

What It Is

This is an aftermarket replacement blade for certain John Deere and compatible riding mowers, designed to cut grass on residential or light commercial lawns. It is 21-1/4 inches long, intended for decks that require that specific length.

Fitment & Compatibility

Before buying, verify three things: 1) Deck size – this blade fits 42-inch or similar decks that use 21-1/4" blades (measure your current blade from tip to tip). 2) Model – it is often used on John Deere models like D100, D105, D110, D120, D125, D130, D140, D150, D155, D160, D170, LA105, LA115, LA125, LA135, LA145, LA155, LA165, L100, L110, L120, L130, and some X300 series. 3) OEM cross-reference – this is an aftermarket blade; check against OEM part numbers like GY20785, GY20806, GY20807, or AM137722. Measure your blade’s center hole diameter (usually 1 inch) and ensure the blade shape matches (straight or offset). Confirm your deck uses a single blade (not a set of two or three).

Key Things to Know

• Quality concerns – The 1.0/5 rating (1 review) suggests poor sharpness, balance, or durability out of the box. Expect possible vibration or premature dulling.
• Installation – Easy for DIY: lift mower, remove center bolt, swap blade, torque to 40-50 ft-lbs. Always use a blade removal tool or block wood to prevent spinning.
• Common gotcha – Aftermarket blades often have thinner steel or inconsistent edge angles. Check for warping before mounting. If vibration occurs after install, the blade may need balancing.
• Sharpening – Not recommended; replace when dull. This blade is likely low-carbon steel and won’t hold an edge long.

Should You Buy It

Skip this blade unless you are on a tight budget and only need a temporary fix. The single 1-star review and lack of better feedback indicate a high risk of poor performance. Spend a few dollars more for a reputable aftermarket brand (e.g., Oregon, MaxPower) or an OEM John Deere blade to get reliable cut quality and longer life.