Selecting the correct carbon fiber yarn requires a deep understanding of tensile strength, modulus, and filament count (k-count). For high-performance structural needs, prioritize High Modulus (HM) or Ultra-High Modulus (UHM) fibers. For general reinforcement, Standard Modulus (SM) is often sufficient. Always verify the filament count (e.g., 1K, 3K, 12K, 24K) as it directly impacts the weave density and resin absorption. Ensure the supplier provides technical data sheets (TDS) confirming the tensile strength (MPa) and elongation at break to match your specific engineering requirements.