A series of epoxy networks were made with molecular weights between crosslinks, M-c, ranging from 380 to 1790 g mol(-1). Resins were cast into thin walled hollow cylinders and tested in stress states ranging from uniaxial compression to biaxial tension. These tests elucidated the effects of stress state, strain rate, and M-c on the yield and fracture response of epoxy networks. Throughout the study, the strain rate a long the octahedral shear plane, (gamma) over dot(oct), was maintained constant independent of stress state, for each failure envelope. The hollow cylinder tests showed that the yield behaviour of epoxy networks can be described by a modified von Mises criterion, tau(y)(oct)=tau(y0)(oct)-mu sigma(m) where tau(g)(oct) is the octahedral shear stress at yield, tau(y0)(oct) is the octahedral shear stress at yield in pure shear, mu is the coefficient of internal friction and V-m is the hydrostatic tensile stress imposed on the sample. Furthermore, these tests showed that changes in (gamma) over dot(oct) and M-c only affect tau(y0)(oct), while mu remains constant. Standard tensile and compression tests were run to confirm the hollow cylinder result and to test the effect of temperature on the yield and brittle response. Tensile tests showed that changes in M-c only affect the glass transition temperature, T-g, of the materials, and the glassy modulus remained independent of M-c. With regard to the yield strength, changes in M-c cause a shift in the T-g of the materials, and the yield strengths of all the materials collapse together at a constant temperature relative to T-g. Finally, yielding of these epoxies was shown to follow an Eyring type flow model over the range of temperatures and strain rates tested.