An investigation was conducted to examine the adhesion and friction behavior of boron nitride films (BN coating, 2 μm thick) on 440‐C bearing stainless steel substrates. The thin films containing the boron nitride were synthesized using an ion beam extracted from a borazine (B3N3H6) plasma. Sliding friction experiments were conducted with BN in sliding contact with itself and various transition metals (Ti, Zr, V, Fe, Ni, Pd, Re, and Rh) at a sliding velocity of 3 mm/min with loads to 0.2 N at room temperature and in a vacuum of 30 nPa. The results of the investigation indicate that the surfaces of ion sputter cleaned BN coating film contain a small amount of oxides and carbides, in addition to boron nitride. The coefficients of friction for the BN in contact with metals have been correlated with the relative chemical activity of the metals. The more active the metal, the higher is the coefficient of friction. The adsorption of oxygen on ion sputter cleaned metal and BN increases the shear strength of the metal–BN contact and increases the friction. The friction for BN–BN contact is a function of the shear strength of the contacts. Ion sputter cleaned BN surfaces exhibit relatively strong interfacial adhesion and high friction. The presence of adsorbates such as adventitious carbon contaminants on the BN surfaces reduces the shear strength of the contact area. In contrast, chemically adsorbed oxygen enhances the shear strength of the BN–BN contact and increases the friction.