Assembly comprising a ball lock pin and at least two structures (51, 52) to be secured against shearing, the ball lock pin comprising - an operating portion, wherein the operating portion forms a handle on which an operator can grip the ball lock pin, - a shaft portion for engagement in the at least two structures (51, 52), and - a locking mechanism, wherein the operating portion and the shaft portion are rigidly connected to one another and the operating portion has a contact surface, in particular a collar, on the end thereof facing the shaft portion, for abutting one of the structures (51, 52), wherein an operating button is formed on the operating portion, by means of which the locking mechanism can be actuated and which can be pressed in an axial direction by the operator, wherein at least one locking ball can be actuated by means of the locking mechanism, and wherein the at least one locking ball protrudes radially from the shaft portion through a recess in the shaft portion in a basic position of the locking mechanism, and the at least one locking ball can fall back radially behind the recess in a release position, characterized in that the at least one locking ball, together with the associated recess, is formed in an upper half of the shaft portion that faces the operating portion, and in that the shaft portion projects through a first structure, wherein the at least one locking ball engages behind a structural edge of the first structure in the basic position, and wherein the shaft portion further projects through a second structure, which is arranged on a side of the first structure that faces away from the operating portion, or projects into the second structure, and the at least one locking ball does not engage behind the second structure, in particular wherein the contact surface abuts the first structure. - an operating portion, wherein the operating portion forms a handle on which an operator can grip the ball lock pin, - a shaft portion for engagement in the at least two structures (51, 52), and - a locking mechanism, wherein the operating portion and the shaft portion are rigidly connected to one another and the operating portion has a contact surface, in particular a collar, on the end thereof facing the shaft portion, for abutting one of the structures (51, 52), wherein an operating button is formed on the operating portion, by means of which the locking mechanism can be actuated and which can be pressed in an axial direction by the operator, wherein at least one locking ball can be actuated by means of the locking mechanism, and wherein the at least one locking ball protrudes radially from the shaft portion through a recess in the shaft portion in a basic position of the locking mechanism, and the at least one locking ball can fall back radially behind the recess in a release position, characterized in that the at least one locking ball, together with the associated recess, is formed in an upper half of the shaft portion that faces the operating portion, and in that the shaft portion projects through a first structure, wherein the at least one locking ball engages behind a structural edge of the first structure in the basic position, and wherein the shaft portion further projects through a second structure, which is arranged on a side of the first structure that faces away from the operating portion, or projects into the second structure, and the at least one locking ball does not engage behind the second structure, in particular wherein the contact surface abuts the first structure.