This study examines the flexural properties of blends containing polypropylene (PP), polybutylene terephthalate (PBT), polyamide 6 (PA6), and ethylene-vinyl acetate (EVA). Virgin polymers were used to investigate three formulations containing 4.8, 9.6, or 14.4 wt% of each engineering polymer, corresponding to combined PBT/PA6 contents of 9.6, 19.2, and 28.8 wt%, respectively. The PBT:PA6 mass ratio remained 1:1, and the EVA content was fixed at 4 wt% in these formulations. Injection-molded specimens were assessed by bending tests described with reference to ASTM D790, and five observations were reported for each formulation and the control. Mean reported flexural stress increased from 36.77 MPa for the control to 50.13 MPa for the formulation containing 14.4 wt% of each polymer. Mean reported strain increased from 7.32% to 12.41%. In contrast, flexural modulus reached its highest mean value, 1466.72 MPa, at 4.8 wt% of each polymer, compared with 1088.15 MPa for the control. Thus, the formulations with the highest reported stress and the highest initial stiffness were different. The results identify composition-dependent bending responses within the tested range, without establishing a universal optimum or a specific phase morphology. Because the reported strains exceed 5%, the test endpoints and compliance with ASTM D790 require clarification before the stress values can be treated as standard-compliant flexural strengths.