91591-3 is a crimping terminal used in industrial electrical assembly applications where solderless wire connections are required. The terminal functions by compressing a wire barrel around stripped wire strands to form a homogeneous metal connection without requiring solder, heat, or flux. Proper crimp quality is achieved through correct selection of wire, terminal, and applicator tool, with specifications including conductor crimp height (CH1), insulation crimp height (CH2), conductor crimp width (CRI), and insulation crimp width (CR2) to ensure straight crimps with no loops or sharp edges. The terminal must meet industry certification standards including vibration testing (16 hours exposure without electrical discontinuity), crimp tensile strength testing, dielectric strength testing, and voltage drop testing to verify homogeneous mass formation and electrical resistance stability. This terminal is commonly used in industrial systems where cost-effective, reliable electrical connections are critical, and proper tool-terminal matching from the same manufacturer ensures lasting performance and compliance with certifications such as MIL-T-7928.