Reed also known as retaining ring or retaining ring, which belongs to a fastener, for installation in the machine, equipment, shaft slot or slot, play a role in blocking the shaft or hole on the left and right parts. The more commonly used axle card (STW) and hole card (RTW), the mainland mainly produces 65MN spring steel, corresponding to the national standard. The domestic quality is better is the production of the spring in Taiwan. China Taiwan Province, the production of the main spring retainer to prevail in Japan, made of SK7 spring steel, retainer also C-type E-type U-shaped.