Hybrid yarns, combining stainless steel with glass fibers, are promising for impact-resistant composites. Inside the yarn, the thermoplastics matrix is provided in the form of endless filaments. Thermoplastics gained popularity as composites' matrix due to recyclability. The study emphasizes customizing adhesion between stainless steel and polypropylene for desired properties in the composites. Tailored adhesion is crucial for optimizing the performance of stainless steel/polypropylene composites. Within this contribution, a selection of adhesion promoters and preventers is analyzed to generate adjustable adhesion between polypropylene matrix and stainless steel filaments. The characterization is fulfilled using contact angle measurements on films of coating agents and coated stainless steel filaments. Furthermore, surface free energy is calculated and theoretical adhesion is analyzed between coating agent and stainless steel filaments and coated stainless steel filaments and polypropylene matrix. The results are validated by single fiber pullout tests.