A metering head for a metering machine or another metering device comprising: • a carrier to which a plurality of parallel attachments for receiving pipette tips are arranged one next to the other, • wherein each attachment has the following features: • a tube having an outwardly protruding, at least partially circumferential supporting projection at the lower end, • a first sleeve which encloses the tube and is axially displaceable on the tube, and • a first elastomer O-ring which encloses the tube, is arranged next to the lower end of the first sleeve and is supported at the bottom on the supporting projection, • a pressure plate arranged above the sleeves and having a plurality of first holes through which the tubes extend, wherein the pressure plate can be displaced along the tubes between a release position at a first distance from the supporting projections and a clamping position at a second distance from the supporting projections, which second distance is less than the first distance, and the pressure plate pushes against the upper edge of the adjacent sleeves of all attachments in the clamping position in such a way that the sleeves are pressed by the lower ends against the adjacent O-rings and the O-rings are flared in order to securely clamp pipette tips pushed onto the attachments, • a first displacement apparatus which is connected to the pressure plate and is designed to displace the pressure plate between the release position and the clamping position. • a carrier to which a plurality of parallel attachments for receiving pipette tips are arranged one next to the other, • wherein each attachment has the following features: • a tube having an outwardly protruding, at least partially circumferential supporting projection at the lower end, • a first sleeve which encloses the tube and is axially displaceable on the tube, and • a first elastomer O-ring which encloses the tube, is arranged next to the lower end of the first sleeve and is supported at the bottom on the supporting projection, • a tube having an outwardly protruding, at least partially circumferential supporting projection at the lower end, • a first sleeve which encloses the tube and is axially displaceable on the tube, and • a first elastomer O-ring which encloses the tube, is arranged next to the lower end of the first sleeve and is supported at the bottom on the supporting projection, • a pressure plate arranged above the sleeves and having a plurality of first holes through which the tubes extend, wherein the pressure plate can be displaced along the tubes between a release position at a first distance from the supporting projections and a clamping position at a second distance from the supporting projections, which second distance is less than the first distance, and the pressure plate pushes against the upper edge of the adjacent sleeves of all attachments in the clamping position in such a way that the sleeves are pressed by the lower ends against the adjacent O-rings and the O-rings are flared in order to securely clamp pipette tips pushed onto the attachments, • a first displacement apparatus which is connected to the pressure plate and is designed to displace the pressure plate between the release position and the clamping position.