the more harden needed excavate substances would lead to large friction force to bucket tooth

　　When control and operate the China bucket tooth pin and bucket tooth to resolve the needed excavate substances, there would produce the relative motion between the bucket tooth and substances, but makes the large squeezing pressure force on surface, and the large friction force between the bucket tooth work surface and needed excavate substances.

　　If the needed excavate substances belongs to more harden rock, stones and concrete, the friction force between the China bucket tooth pin working surface and substances would be larger too, so because of the continuous excavate motions, the working surface for bucket tooth would appear the different grade abrasion hurt, and the large depth furrow groove would appeared next.

　　Due to the positive pressure on front working surface of China bucket tooth pin is larger than back working surface, so the abrasion damage hurt for front working surface is more serious too, and the main reason lead to bucket tooth lose efficiency problem is because of the external mechanical factors.