PRESS-FIT, FRICTION-RETENTION COUPLING ASSEMBLY BETWEEN HARD, INFLEXIBLE MATERIAL COMPONENTS

An outer component and an annular collar can be formed of materials having a Rockwell R hardness of at least 120. The outer component can have a recess, including an outer component mating wall. The annular collar can include an annular collar mating wall, including at least three protrusions. A recess can surround each protrusion so that an overall protrusion height between a base of the protrusion and a distal end thereof is greater than a protruding distance between an outer diameter of a cylindrical outer surface of the annular collar mating wall and the distal end of the protrusion. The number and configuration of the protrusions can be designed to provide a press-fit insertion force of 50 Newtons or less, and to provide a friction retention force sufficient to retain the annular collar within the recess under its own weight, throughout relevant tolerance ranges for the mating walls.