This paper presents friction tests results of AISI 1006 low-carbon steel and an AISI 52100 bearing steel using a spiral pin-on-disk apparatus. 3 mm diameter pins on two average (0.06 or 0.20 mm) diameters glass particle coated abrasive paper were used. The normal force applied was 20 N, the tangential sliding speed was 0.08 m/s, and the radial pin movement was 20 mm/min. The micro-indentation hardness of the pins was measured before and after testing. In general, the higher the strain hardening, the higher was the friction coefficient. For AISI 1006, which wore in a severe regime, the strain hardening intensity depended on the abrasive particle size. For AISI 52100, which wore in a mild regime, the particle size had no effect. Tests on AISI 1006 exhibited paper loading, but tests on AISI 52100 exhibited abrasive particle fragmentation. [Copyright &y& Elsevier]