A piston (510) comprising a cylindrical body (511) having a front axial end that is closed by a front wall (513), said hollow cylindrical body (511) including an outside surface that is provided with at least one secondary sealing profile (610), said front wall (513) including a front axial outside surface (631) that is provided with a coating (635), advantageously a film made of ethylene tetrafluoroethylene, said front wall (513) including a primary sealing profile (630) on its radially-outer edge, said front wall (513) and said cylindrical body (511) being made of different materials, said hollow cylindrical body (511) being overmolded on said front wall (513), said front axial outside surface (631) of said front wall (513) including a deformation profile (633) that is arranged radially inside said primary sealing profile (630) of said front wall (513), said deformation profile (633) being adapted to deform radially so as to make it easier to insert and/or to slide said piston (510) into a syringe body.一種活塞包含具有前軸向端的圓柱體,前軸向端被前壁封閉,中空的圓柱體包含具有至少一個次級密封剖面的外表面,前壁包含具有塗層之前軸向外表面,為乙烯-四氟乙烯製成的膜較佳,前壁包含位於其輻射狀外部邊緣上的初級密封剖面,前壁與圓柱體由不同的材料製成,中空的圓柱體在前壁上被二次成型,前壁的前軸向外表面包含變形剖面,變形剖面輻射狀地排列於前壁的初級密封剖面內部,變形剖面適用於輻射狀變形,從而更容易插入與/或滑動活塞到注射器主體內。510‧‧‧活塞511‧‧‧圓柱體512‧‧‧後軸端513‧‧‧前壁515‧‧‧內部容積610‧‧‧次級密封剖面615‧‧‧內部螺紋630‧‧‧初級密封剖面631‧‧‧前軸外表面633‧‧‧變形剖面635‧‧‧塗層700‧‧‧分隔線1810‧‧‧軸向尖端
