A door check device for installation between a vehicle body and a vehicle door that swings in opposing opening and closing directions relative to the vehicle body is provided. The door check device comprises a housing assembly and an elongated link member. The housing assembly comprises a first mounting structure, and a plastic housing member containing a biasing structure, a first link member engaging structure and a second link member engaging structure therein. The plastic housing member has a first engagement structure. The first mounting structure includes a plastic cover that has a second engagement structure that is constructed and arranged to engage with the first engagement structure to form an area of contact therebetween. The plastic housing member and the plastic cover are secured by fusion of the materials to each other in the area of contact between the first and the second engagement structures.