Seat recliner for vehicle

A seat recliner for a vehicle, the seat recliner comprising:

• a first flange having a first engagement portion comprising gear teeth, the first engagement portion being positioned on one surface of the first flange;
• a second flange having a second engagement portion comprising gear teeth, the second engagement portion being positioned on one surface of the second flange;
• an elastic member positioned between the first flange and the second flange;
• a retainer positioned adjacent to the first flange;
• a shaft penetrating a center of the first flange, a center of the second flange, and a center of the retainer;
• and
• a pressing member coupled to the shaft and positioned between the first flange and the retainer, the pressing member being configured to allow the first engagement portion and the second engagement portion to engage with or disengage from each other while being rotated in a locking direction or an unlocking direction by an operation of the shaft.