The influence of drawing speed taken as the index of tensile force during preparation on the internal stress of glass-coated microwires with nominal composition Co68.2Fe4.3Cr3.5Si13B11 and Fe45Co20Ni10Si9B16 is presented. The obtained results show that drawing speed has influence on the critical length to observe magnetic bistability and the value of switching field. Further researches show that the internal tensile stress increases by 220–300 MPa when the drawing speed rises by 100 m/min. This study confirmed the existence and magnitude of internal stress induced by tensile force during preparation proposed by Chiriac et al.