Toro 131-3939-03P Timecutter 42" Blade Kit

What It Is

This is a genuine Toro OEM blade kit (part 131-3939-03P) designed for 42-inch TimeCutter zero-turn mowers. It includes three blades for a single cutting deck, intended for residential lawn maintenance on medium-to-large properties.

Fitment & Compatibility

Before buying, confirm your mower has a 42-inch stamped deck (not fabricated). This kit fits Toro TimeCutter models like the SS4225, SS4235, MX4250, and 75742. It also works on certain Toro TimeCutter SW4200 and 4200-series models. Measure your existing blade length: these are 16.5 inches long with a 1-inch center hole and 0.75-inch offset. They are not compatible with 48-inch or 54-inch decks, or with non-Toro brands like John Deere or Husqvarna. Always verify your mower’s model number (stamped on the deck or frame) against Toro’s compatibility chart.

Key Things to Know

• OEM quality matters – These are Toro-manufactured blades with balanced, heat-treated steel. Aftermarket replicas often warp or dull faster.
• Installation difficulty – Easy to moderate. You’ll need a socket wrench and a blade removal tool (or a block of wood to jam the blade). Torque to 30-50 ft-lbs.
• Sharpness out of the box – They come sharp but not razor-sharp; a quick hone before first use improves cut quality.
• Common gotcha – Do not mix these with other blade types (e.g., mulching or gator blades) on the same deck. Uneven lift can cause vibration and poor cut.

Should You Buy It

Buy this kit if you own a Toro TimeCutter 42-inch mower and want a direct OEM replacement that guarantees fit, balance, and durability. It’s ideal for homeowners who want a hassle-free swap without measuring or testing aftermarket alternatives. If you need mulching or bagging-specific blades, consider Toro’s separate mulching kit for the same deck.