Hair-PIN Motor Flat Wire is a rectangular (flat) enameled copper wire specifically designed for hairpin winding technology in electric motors. Instead of using traditional round magnet wire wound continuously around the stator, hairpin motors use precisely formed U-shaped ("hairpin") flat conductors that are inserted into the stator slots, twisted, and laser welded together to form the winding.

This technology has become the preferred solution for electric vehicles (EVs), hybrid electric vehicles (HEVs), industrial servo motors, and high-efficiency traction motors because it enables higher power density, improved efficiency, and better automated manufacturing.
 

A hairpin winding consists of rigid, rectangular copper conductors bent into U-shaped pins.

The manufacturing process typically follows these steps:

• Produce insulated rectangular magnet wire.
• Cut the wire to an exact length.
• Bend it into a U-shape (hairpin).
• Insert the hairpins into the stator slots.
• Twist the wire ends.
• Laser weld the joints.
• Apply insulation and resin impregnation.

Compared with traditional random-wound round wire, this process is highly automated and suitable for large-scale EV motor production.