Materials scientists and design engineers considering the use of composites molded from sheet molding compound (SMC) for structural applications need reliable mechanical property data for these composites. In response to this need, the mechanical properties of a well documented, carefully prepared SMC-R50 composite over a temperature range of -40°C to 121°C are reported. The properties determined include engineering constants (Young's modulus, shear modulus, and Poisson's ratio), thermal coefficient of expansion, tensile fatigue, tensile creep, and ultimate strengths in tension, compression, shear and flexure. All tests are based on one composite material, thus, conclusions about the relationship between different mechanical properties can be made. For example, the tensile and compressive moduli of SMC-R50 composite are virturally the same. Also, Young's modulus, shear modulus and Poisson's ratio, obey an established equation relating these constants. In addition, this study establishes the existence of a fatigue limit for SMC-R50 composite.