The global behaviour of the cold pressing process of iron powder is dependent on the material response in the powder as well as the friction between the powder and the tool walls. Both the behaviour with respect to the material response and the friction effects are dependent on the lubricant used in the powder mixture. Normally, solid phase lubricants are mixed into the iron powder. It is assumed that the local heat generated in the microscopic contact areas between the powder and the tool walls is partly responsible for the functionality of the lubricant. The microscopic interaction between powder, lubricant and tool wall at the point of contact is described by relations between the friction coefficient and a combination of state variables, e.g. relative velocity, pressure and powder density. The relations are established by use of tribological classifications of the lubricant as well as the mixture of lubricant and iron powder. Finite element simulations of pressing experiments are used for studying the influence of the frictional relations on the global pressing behaviour.