This work presents an experimental investigation of the response of “neat,” unscrimmed FM‐73 adhesive under mechanical loads at various stress levels and over the 30–60°C temperature range. The methodically acquired data provide the basis for a material characterization based on a specific model of nonlinear viscoelastic response. In particular, it is shown that it is essential to include transient‐temperature testing in the characterization scheme. Subsequent tests were performed under conditions of fluctuating loads and temperatures in order to verify the predictive capabilities of the model and characterization scheme. Satisfactory results were obtained.