The thermomechanical contact between beryllium cubes and Type 316 stainless steel was analyzed for various values of applied pressure normal to the interface. If we neglect the influence of gap on the interface resistance, finite element analyses show that a simple one-dimensional analysis can lead to serious underestimation of the maximum temperature of the beryllium. A two-dimensional analysis underpredicts the maximum gap created at the interface, compared with a full three-dimensional analysis. Thus, it also significantly underpredicts the maximum temperature of the beryllium.