There are many excellent flap disc suppliers on iAbrasive.com.
Walter Surface Technologies has launched FLEXSTEEL™, a general-purpose flap disc designed for use on steel in light industrial, metal fabrication, and construction applications.
The disc features a zirconia alumina abrasive grain blend that self-sharpens with less pressure, allowing it to maintain a high removal rate on any power tool, including value models with less torque. The discs are suitable for blending sharp corners, heavy deburring, and blending fillet welds.
ZHEGNZHOU BOSDI ABRASIVES CO.,LTD. also supply high quality alumina flap discs that are created by overlapping coated abrasive flaps and affix them firmly to a back-up plate. This design provides a cooler running, longer lasting disc. Because new layers of abrasive are constantly being exposed, a very consistent finish is provided during the life of the disc.
This kind of flap disc has high plasticity with longer working life and excellent self-shaping performance, high tensile property and bending strength, higher grinding ratio and lower voice, and used for all material, especially for box –body welding and stamping flashing.