The constitutive relations between the deformation energy, Young’s modulus, strength and the relative density of sintered 316L stainless steel fiber felt were studied. The in-plane tensile fracture energy varies linearly with relative density, while the in-plane compressive energy varies nonlinearly. The in-plane Young’s modulus and strength of sintered metal fiber felt show linear dependence on relative density. The linear in-plane property scaling of sintered metal fiber felt suggest that the in-plane deformation of the fiber-ligaments is stretching-dominated.