1. The problem statement, all variables and given/known data I'm trying to determine the friction of a pin joint that will be loaded differently depending on the position of the linkage. 2. Relevant equations I know the equation for frictional force is F="mu"*N, where "mu" is either the coefficient of static or kinetic friction depending on if the surface is in motion, but I'm not sure how to apply that to a pin joint. 3. The attempt at a solution Im assuming the pin to be "loose fitting" so that friction will be basically limited to a point on the surface. And if I know the force applied to the joint, can I just take that force as N in the equation and and find the appropriate "mu" to solve for the frictional force? I'm just looking for a decent approximation for the friction.