Replaces Exmark 135-0413-S Medium Lift Blades Commercial S Series 21 Inch 3 Pack, Red

What It Is

This is a set of three 21-inch medium lift blades (OEM reference Exmark 135-0413-S) designed for Exmark Commercial S Series zero-turn mowers. They are an aftermarket replacement intended for high-volume cutting of thick or tall grass on commercial turf.

Fitment & Compatibility

Before buying, confirm three things:

1. Deck size – these are 21-inch blades, so they only fit a 21-inch cutting deck.
2. Brand/model – they replace Exmark Commercial S Series blades (e.g., Lazer Z S-Series). They will not fit other brands or residential Exmark decks without verifying the blade center hole and drive pin pattern.
3. OEM vs aftermarket – aftermarket blades may have slight dimensional differences. Measure your old blade’s length (21 in), center hole diameter (typically 5/8 in or 7/8 in), and thickness (approx. 0.204 in). Check that the lift profile matches your deck’s discharge design (side or rear).

Key Things to Know

• Quality – These are likely hardened steel but may not hold an edge as long as genuine Exmark blades. Expect to sharpen more frequently in sandy or abrasive conditions.
• Installation – Standard bolt-on. Use a torque wrench (50–70 ft-lbs typically) and thread locker. Re-torque after the first 15 minutes of use.
• Gotcha – Medium lift blades produce less vacuum than high-lift blades. If you bag or need fine clippings, consider high-lift alternatives. For side-discharge mulching, these are fine.
• Pack size – Three blades per pack, enough for one 21-inch deck.

Should You Buy It

If you own an Exmark Commercial S Series with a 21-inch deck and need a budget-friendly set of medium lift blades for general cutting (not bagging or mulching), this three-pack is a solid value. For heavy commercial use, stick with OEM for longer life.