Hi @George P Johnson I am working on a contact between two surfaces (Both of steel materials having hollow circular section)having clearance of 0.1 mm . I was using TYPE 19 contact but facing issues in the same and one of the node in the interface reduces time step. Parameter sued with TYPE 19: Istf :4, Fric: 0.1, Gap min: 0.1, Inacti6, Iform2 .   Any other parameters recommended for solving type 19 ?   Thank you