A male fluid line connector configured to engage a female fluid line connector, the male fluid line connector comprising: a body including a first end configured to be connected to a fluid line, a tapered second end opposed to the first end, the second end configured to be inserted into and form a fluid-tight connection with the female fluid line connector, and a body longitudinal axis that extends between the first end and the second end, and a locking collar including a locking collar first end, a locking collar second end opposed to the locking collar first end, internal threads provided on an inner surface of the locking collar adjacent to the locking collar second end, and through holes extending between the inner surface and an outer surface of the locking collar, wherein the through holes are elongated in a direction parallel to the body longitudinal axis and reside adjacent the locking collar second end so as to interrupt the internal threads, wherein the locking collar first end is connected to the body in a manner such that the locking collar can rotate about the body longitudinal axis, and the locking collar is configured such that when the second end of the body is inserted into the female fluid line connector, the locking collar second end engages an outer surface of the female fluid line connector and is deformed by the engagement. a body including a first end configured to be connected to a fluid line, a tapered second end opposed to the first end, the second end configured to be inserted into and form a fluid-tight connection with the female fluid line connector, and a body longitudinal axis that extends between the first end and the second end, and a first end configured to be connected to a fluid line, a tapered second end opposed to the first end, the second end configured to be inserted into and form a fluid-tight connection with the female fluid line connector, and a body longitudinal axis that extends between the first end and the second end, and a locking collar including a locking collar first end, a locking collar second end opposed to the locking collar first end, internal threads provided on an inner surface of the locking collar adjacent to the locking collar second end, and through holes extending between the inner surface and an outer surface of the locking collar, wherein the through holes are elongated in a direction parallel to the body longitudinal axis and reside adjacent the locking collar second end so as to interrupt the internal threads, wherein a locking collar first end, a locking collar second end opposed to the locking collar first end, internal threads provided on an inner surface of the locking collar adjacent to the locking collar second end, and through holes extending between the inner surface and an outer surface of the locking collar, wherein the through holes are elongated in a direction parallel to the body longitudinal axis and reside adjacent the locking collar second end so as to interrupt the internal threads, wherein the locking collar first end is connected to the body in a manner such that the locking collar can rotate about the body longitudinal axis, and the locking collar is configured such that when the second end of the body is inserted into the female fluid line connector, the locking collar second end engages an outer surface of the female fluid line connector and is deformed by the engagement.