AC04105 8" Replacement Heavy Duty Blade for Ryobi Brush Cutters RY254BC, RY40255-BRC and Expand-It Brush Cutter Attachment RYBRC77 - Reversible Steel Tri-Arc Brush Cutting

What It Is

The AC04105 is a heavy-duty 8-inch tri-arc brush cutting blade designed for Ryobi brush cutters and string trimmer attachments. It replaces standard nylon line for cutting thick weeds, brambles, and light brush up to about 1/2-inch thick.

Fitment & Compatibility

This blade fits Ryobi RY254BC, RY40255-BRC, and the Expand-It Brush Cutter Attachment RYBRC77. It uses a standard 1-inch (25.4mm) arbor hole. Before buying, confirm your unit’s shaft type (straight vs. curved) – this blade works only with straight-shaft models that accept tri-arc blades. Also verify your trimmer head has a blade-ready mount (not all string trimmer heads can swap to a blade). If your model uses a different attachment system (e.g., RY40250), it will not fit.

Key Things to Know

• Material & durability: Made from hardened, reversible steel – you can flip it to get a second cutting edge when one side dulls.
• Installation: Requires a 10mm or 13mm wrench (depending on your model) and a hex key to lock the spindle. No special tools beyond that. Tighten to 20-25 ft-lbs.
• Safety note: Always remove the spark plug wire before installing. Use a blade nut with a lock washer; do not overtighten or you risk stripping the crankshaft.
• Common gotcha: The blade is 0.100-inch thick – it will not fit trimmer heads designed for thinner .080-inch blades. If your head has a blade lock pin, you may need to remove it or use a different adapter.

Should You Buy It

If you regularly clear overgrown brush, blackberry vines, or saplings with your Ryobi straight-shaft brush cutter, this blade is a solid, affordable upgrade over string line. It’s reversible, holds up well against tough vegetation, and installation is straightforward for anyone comfortable with basic wrench work. Skip it if you only mow grass or have a curved-shaft trimmer.