2. 20s-30s--bean, such as soybean, rice, corn niblet.
3. 40s-60s--hard things, such as pearl, roots.
4. about the material with fiber, the fiber cannot be crushed entirely, so there powder will be floccus.
5. about the nuts, and other things with oil. It' better to grind 2-3 seconds, then stop. again, grind 2-3 seconds, then stop. again.... It's to prevent the powder stick to the cabin. Because when the machine working, the speed of the motor is very quickly, and the material will collide with blade and cabin , then it will generate heat. And the material is oily, it will stick to the cabin easily.