Detail: Two pieces of metal colliding in space, become permanently linked.
When 2 pieces of metal collide in space, they become permanently stuck to each other, if they don’t have any coatings on them. Amalgamation of metals is caused by the space vacuum, which is not possible on earth where an oxidation layer covers the metal. Space stations don’t have this problem because all the materials have already undergone some level of oxidation on earth. The process of space metal amalgamation is known as cold welding.