This article shows how fiber properties obtained by the compression refining of bleached softwood pulp refined using a KID 300 refiner differs from traditional bar refining. A KID refiner is a stone crusher that has been modified to refine fiber, and it offers a refining method that could be used at the mill scale. This study showed that compression refining caused more internal fibrillation compared with blade refining and improved the pulp’s ability to be beaten. Net energy consumption in compression refining was less than that of bar refining. Compression refining yielded pulp with shorter fibers and a higher number of fines, kinks, and curves. Still, the strength properties of the paper were the same level as bar-refined pulp, probably due to the higher internal fibrillation and flexibility of the fibers. It was also shown that the low field time-domain nuclear magnetic resonance (TD-NMR) method was capable of measuring the porosity and internal fibrillation of the fiber.