Echo 99944200047 3-Tooth Grass & Weed Blade (20mm Arbor)

What It Is

The Echo 99944200047 is a 3-tooth, 8-inch diameter grass and weed blade designed for gas-powered brush cutters and string trimmers with a 20mm arbor. It excels at cutting heavy brush, thick weeds, and saplings up to about 1 inch thick, replacing string heads in dense vegetation.

Fitment & Compatibility

• Arbor size: Requires a 20mm shaft diameter. Measure your trimmer’s output shaft—most Echo, Shindaiwa, and some Husqvarna and RedMax models use 20mm, but common consumer trimmers often have 25.4mm (1-inch) arbors.
• Blade diameter: 8 inches. Ensure your trimmer’s guard and debris shield can accommodate this size. Check for minimum clearance around the guard opening.
• OEM vs aftermarket: This is an OEM Echo part, so it’s guaranteed to fit Echo and Shindaiwa models with a 20mm arbor. Aftermarket blades may be cheaper but often require additional washers or bushings for proper centering.
• Deck size: Not applicable—this is for handheld trimmers/brush cutters, not mower decks.
• What to measure: Confirm your trimmer’s arbor size (look for “20mm” in manual or on shaft), and verify that your unit has a blade-capable clutch and guard (most brush cutters do, but many string trimmers do not).

Key Things to Know

• Installation difficulty: Moderate. You’ll need a blade locking tool or a hex wrench to hold the shaft, plus a socket for the nut. Torque to 25–35 ft-lbs per Echo specs. Reverse threading on some models—check your manual.
• Cutting performance: Three teeth provide aggressive cutting but can kick back on thick stalks. Use a steady, sweeping motion; do not force the blade straight into dense brush.
• Common gotcha: Using this blade on a trimmer not rated for blades will damage the clutch and void warranty. Always verify your unit has a blade-ready guard and clutch.
• Durability: Carbide-tipped teeth hold an edge well, but hitting rocks or concrete will dull them quickly. Sharpen with a file or replace when chipped.

Should You Buy It

If you regularly clear heavy weeds, blackberry brambles, or small saplings with an Echo or Shindaiwa brush cutter that has a 20mm arbor, this blade is a solid upgrade from string. It’s not for light grass or for trimmers with smaller arbors—stick to string heads for those jobs. For $36, it’s a durable, OEM-fit solution that outperforms most aftermarket options in both safety and longevity.