The well inlet configuration is the most extreme form of pre-compacting in the hole of a die. The well is a cylindrical hole drilled from the inside of the die, to a maximum of 30% of the total hole length and can be upto two times the diameter of the pellet diameter.
It is used with products which:
   a) Need extra compression because of high oil content (lubrication)
   b) Need extra compression in order to create mechanical shear action to form a
        hard pellet (dry heat production)
For extremely bulky raw materials that are difficult to get into the original small hole diameter- shallow wells are often used.