A tank manufactured from a plastic material and having a reinforcement member. The reinforcement member having a first portion made of a first material weldable to the plastic material of the tank; and a second portion made of a second material having a tensile stress at break which is three to nine times larger than the tensile stress at yield of the first material. The second portion having at least one through-hole, and the first material extends in said at least one through-hole and at opposite sides of said second portion adjacent said at least one through-hole.