90599025 Replacement Trimmer Head Compatible with Dewalt DCST920B,DCST920P1,DCST990B,DCST990H1,DCST990M1,DCST925,DCST925M1 with Pre-Wound 0.080" 20Ft Line

What It Is

This is a replacement bump-feed trimmer head designed for DEWALT 20V MAX string trimmers. It comes pre-wound with 0.080-inch, 20-foot line, so you can swap it on without spooling your own line.

Fitment & Compatibility

Before buying, verify your trimmer model is one of these: DCST920B, DCST920P1, DCST990B, DCST990H1, DCST990M1, DCST925, or DCST925M1. This head is a direct replacement for the OEM part (DEWALT part number N588321). It uses a standard left-hand thread (tightens counter-clockwise). If your trimmer has a different shaft diameter or a different attachment system (e.g., universal quick-connect), this will not fit. Measure the existing head diameter (this one is roughly 4.5 inches) to ensure it matches your cutting swath preference.

Key Things to Do

• Check the line thickness: This head is pre-loaded with 0.080″ line. If you need thicker line (0.095″ or 0.105″) for heavy weeds, you’ll have to re-spool it yourself. The head can accept up to 0.095″ line.
• Installation is simple: Unscrew the old head (turn clockwise to remove), then screw this one on (turn counter-clockwise to tighten). No tools required, but make sure the trimmer is off and the battery is removed.
• Bump-feed mechanism: Tap the head on the ground to advance line. Some users report the spring can be stiff at first—tap firmly. If the line doesn’t advance, check that the line isn’t tangled inside.
• Pre-wound convenience: You get one spool ready to go. Replacement spools (sold separately) are cheap, but you can also re-spool this head with bulk line.

Should You Buy It

If your DEWALT trimmer’s original head is worn, cracked, or just empty and you want a quick swap without winding line, this is a decent budget option. At $25.99 it’s cheaper than OEM, but the 3.9-star rating suggests occasional quality control issues (e.g., line breaking prematurely). Best for light-to-medium trimming on smaller yards.