Selecting the correct parts requires distinguishing between high-speed industrial requirements and domestic versatility. For industrial machines, prioritize hardened steel components (like rotary hooks and needle bars) that can withstand 5,000+ RPM without thermal deformation. For domestic parts, focus on compatibility with major brands (e.g., Singer, Brother, Janome) and ensure the surface finish is smooth to prevent snagging on delicate fabrics. Always verify the part number (OEM) to ensure a 100% match with the machine model.