PA is a general term for polyamide plastics, which all have amide groups in their structure and share similar properties. Their overall appearance characteristics are: they are all types of tough, horny materials, ranging from slightly yellow transparent to opaque. Common nylon is a crystalline plastic, but there is also amorphous transparent nylon. Nylon can continue to burn or slowly extinguish after being removed from the flame, with the flame tip appearing golden and the base blue. When burning, the material melts and drips, bubbles, and emits a smell similar to burned feathers or nails. The common mechanical properties of PA include toughness, high surface hardness, tensile strength, impact resistance, fatigue resistance, and resistance to folding.Used in machinery, instruments, automotive parts, electronics, electrical, rail, home appliances, communication, textile machinery, sports and leisure products, oil pipes, oil tanks, and some engineering products. Electronic & Electrical: connectors, spools, timers, cover fuses, switch bases, door handles, oil tank lids, air intake grilles, water tank covers, lamp sockets. Industrial Parts: chair seats, bicycle wheel frames, roller skate bases, textile shuttles, pedals, pulleys.