The fundamental scheme of formulation of the amount of metal transfer and wear is based upon the theory suggested in the previous paper [J. Appl. Phys.23, 1011–1019 (1953)]. The basic terms used in formulating metal transfer and wear are (1) the potential amount of metal transferMt*; (2) the mechanical factor of the chance of metal transfer &phgr;m; (3) the thermal factor of the chance of metal transfer &psgr;&thgr;; and (4) the adhesion factor of the chance of metal transfer Xa. The expression for the amount of metal transferMtfrom one specimen to another isMt=Mt*&phgr;m&psgr;&thgr;, when &psgr;&thgr; is bigger than Xa, and isMt=Mt*&phgr;mXawhen Xais bigger than &psgr;&thgr;. The equation for the amount of wearMwrepresented by the weight loss of a specimen isMw=Mt*&phgr;m(1‐&psgr;&thgr;), when &psgr;&thgr; is bigger than Xa, and isMw=Mt*&phgr;m(1‐Xa), when Xais bigger than &psgr;&thgr;.