Ryobi RAC108 Tri-Arc™ Blade (20 cm)

The Ryobi RAC108 Tri-Arc™ 20 cm blade is a high-performance accessory designed to tackle thick vegetation, brambles, and small shrubs where standard nylon line would fail. Its three-tooth shape is engineered to provide an optimal balance between cutting power and vibration reduction.
Features and Technical Specifications

•     Tri-Arc™ Design: The three-point geometry ensures clean cuts and reduces the risk of jamming in tough brush.
•     Material: High-quality hardened steel for long-lasting edge retention.
•     Dimensions: 20 cm diameter, ideal for maintaining high rotational speeds.

    Compatibility:

•         Electric/Hybrid/Battery models: RBC1020, RBC1226i, RBC18X20B4, OBC1820B.
•         Universal for most Ryobi petrol brushcutters (always verify the center bore diameter, typically 25.4 mm).
•         EAN Code: 4892210818621
•         Product Code: 5132002650

Assembly Instructions (Fitting)

•     Safety First: Wear heavy-duty protective gloves. If using a petrol unit, disconnect the spark plug; if using a battery unit, remove the battery pack.
•     Shaft Preparation: Remove the Bump-Feed head (if installed) by locking the gear shaft. Insert a hex key or the locking pin into the dedicated slot on the gear head.
•     Positioning the Blade: Place the RAC108 blade onto the upper flange of the shaft. Ensure the blade is perfectly centered on the flange seat.

    Hardware Installation:

•         Install the lower flange (cupped washer).
•         Place the nut protector/cap (if provided with your model).
•         Screw on the securing nut. Note: Most brushcutters use a left-hand thread, meaning you must turn it counter-clockwise to tighten.
•        Final Tightening: Re-insert the locking pin to hold the shaft still and tighten the nut firmly using the socket wrench provided with your tool.

Disassembly Instructions (Removal)

•     Lock the Shaft: Insert the locking pin or hex key into the gear head slot to prevent the blade from spinning.
•     Unscrewing: Use the socket wrench to unscrew the center nut. Turn it clockwise (due to the reverse threading).
•     Removing Components: Remove the nut, the protector, the lower flange, and then carefully slide off the Tri-Arc™ blade.
•     Cleaning: Before installing a different accessory, clean the shaft and flanges of grass debris or dirt to prevent future vibrations.

Maintenance Tips

•     Sharpening: You can sharpen the blade edges with a flat file, maintaining the original angle. Sharpen all three teeth equally to maintain balance.
•     Inspection: If the blade shows cracks, bends, or chipped teeth, replace it immediately. Never attempt to weld or repair a damaged blade.
•     Storage: After use, clean the blade and wipe it with a lightly oiled cloth to prevent rust.

    Important:

Always ensure that the safety guard installed on your brushcutter is the one designated for metal blade use. This is usually different from the guard used for nylon line.