DeWalt DW8306 4-1/2 in. Type 29 Zirconia Flap Disc (40 Grit) Review (2026)
By Nate Sawyer, Editor · Updated July 2026
DIYPicks is reader-supported. As an Amazon Associate and affiliate of home-improvement retailers, we may earn a commission when you buy through links on our site — at no extra cost to you. This never affects our recommendations.
- Weld blending
- Finishing
- Deburring
A 4-1/2 in. Type 29 zirconia flap disc (40 grit) that blends welds and finishes metal in one step, for a smoother result than a grinding wheel. The angled backing gives a natural 15-25 degree work angle, and the self-sharpening cloth outlasts resin fiber discs. It removes metal slower than a grinding wheel, and the 40 grit leaves scratches.
Pros
- Zirconia flaps blend welds and strip finish while leaving a smoother, more controlled surface than a grinding wheel
- Type 29 angled backing gives a natural 15 to 25 degree work angle for edge work and blending
- Self-sharpening cloth removes material fast and lasts far longer than resin fiber sanding discs
Cons
- Removes metal more slowly than a dedicated 1/4 in grinding wheel on heavy weld beads
- 40-grit leaves scratches that need a finer disc or sandpaper before paint or polish
- Flaps wear unevenly and shed if you dig the edge in, shortening disc life
Specifications
| Type | Type 29 (angled) flap disc |
|---|---|
| Diameter | 4-1/2 in |
| Grit | 40 (coarse) |
| Arbor | 7/8 in |
| Material | Zirconia alumina cloth |
| Best for | Blending welds and finishing metal in one step without gouging |