8TEN LawnRAZOR Blade Set for Toro TimeCutter SW4200 ZS4200S ZS4200T 131-3938-03 42 Inch Deck (Low Lift) 2 Pack

What It Is

The 8TEN LawnRAZOR Blade Set (2-pack) is a low-lift replacement blade designed for Toro TimeCutter SW4200, ZS4200S, and ZS4200T zero-turn mowers with a 42-inch cutting deck. It’s a direct aftermarket alternative to OEM blade 131-3938-03, optimized for dry, sandy, or fine-grass conditions where less lift and reduced dust are preferred.

Fitment & Compatibility

Before buying, confirm your deck is 42 inches (not 50 or 60). The blade fits Toro TimeCutter SW4200 (model 74720, 74721), ZS4200S, and ZS4200T only—not other Toro series or brands. Check your OEM blade number: it must be 131-3938-03 (low-lift). Measure your blade length: 21 inches, center hole 1 inch diameter, with a 7-point star spindle pattern. If your mower uses a different spindle or has a high-lift OEM blade (e.g., 131-3938-04), this set won’t work.

Key Things to Know

• Quality: 8TEN blades are made from heat-treated boron steel, similar to OEM, and pre-sharpened. Expect 20-30 hours of use before dulling in normal conditions.
• Installation: Easy swap—remove the center bolt, align the star pattern, and torque to 70-90 ft-lbs. No adapter or special tools needed. Always disconnect the spark plug first.
• Low-Lift Trade-off: These blades produce less suction, so they’re quieter and kick up less dust, but they won’t bag wet or tall grass well. Use for dry, fine lawns only.
• Common Gotcha: Double-check your spindle pattern. Some Toro decks use a 5-point star; these require a 7-point star. If your spindle is worn or damaged, replace it before installing new blades.

Should You Buy It

If you own a Toro TimeCutter 42-inch deck with low-lift OEM blades (131-3938-03) and mow a dry, sandy, or fine lawn where reduced dust and noise matter more than bagging performance, this is a solid, cost-effective replacement. Not for wet grass, thick turf, or high-lift decks.